Process Chamber Research Articles

Productivity Comparison of Wafer Transport Architectures in PVD Tools Used for Fan-Out Packaging RDL Barrier/Seed Formation

Abstract Physical Vapor Deposition (PVD) systems are widely used in the semiconductor fabrication industry, both for front-end applications in the wafer fab and for back-end applications at device packaging houses. In fan-out wafer level packaging (FOWLP), and in fan-out panel level packaging (FOPLP), sputter deposited Ti and Cu are the base on which electroplated copper Redistribution Layers (RDLs) are built. For these RDL barrier/seed layers, PVD cluster tools, wafer transport architectures that have been widely used since the mid-1980s, are the current Process of Record (POR) in advanced packaging; however, these tools typically operate in a regime where wafer transport is robot-limited to approximately 50 wafers per hour, which limits overall throughput and greatly influences Cost of Ownership (COO) for the sputter deposition step(s), because the central handling robot occupied with a transfer from the Ti PVD module to the Cu PVD module, for example, has no opportunity to be doing anything other than that specific transfer. Other wafer transport architectures are more efficient from a wafer handling perspective. In linear transport carrier-based PVD tools, wafers or panels passing through the system benefit from a mechanical transfer time budget that is considerably less than for a cluster tool. Transport time overhead per wafer on linear transport systems is quite low, and scheduler software optimization becomes less onerous too, as a result of the simpler wafer transport architecture. We analyzed the relative throughput of cluster and linear transport PVD tools for a typical FOWLP barrier/seed layer (1000Å Ti / 2000Å Cu) sputter deposition process, and present details here of how the time spent moving wafers to various processing chambers affects overall system productivity. In the case of the cluster tool architecture, with its central wafer handling robot, wafer throughputs are approximately 50 wafers per hour, while on the linear transport system wafer throughputs as high as 240 wafers per hour are possible. The significant difference in system throughputs greatly affects the relative Cost of Ownership (COO) per wafer processed, with the linear transport system returning COO results that are less than half those of the typical cluster PVD tool.

Laser additive manufacturing of Zn porous scaffolds: Shielding gas flow, surface quality and densification

Zn based metals have exhibited promising prospects as a structural material for biodegradable applications. Pure Zn porous scaffolds were produced by laser powder bed fusion (LPBF) based on data files of designing and CT scanning. Massive Zn evaporation during laser melting largely influenced the formation quality during LPBF of Zn metal. The metal vapor in processing chamber was blown off and suctioned out efficiently by an optimized gas circulation system. Numerical analysis was used to design and testify the performance of gas flow. The surface of scaffolds was covered with numerous particles in different sizes. Processing pores occurred near the outline contour of struts. The average grain size in width was 8.5 μm, and the hardness was 43.8 HV. Chemical plus electrochemical polishing obtained uniform and smooth surface without processing pores, but the diameter of struts reduced to 250 μm from the design value 300 μm. The poor surface quality and processing pores were resulted by the splashing particles included spatters and powders due to the recoil force of evaporation, and the horizontal movement of liquid metal due to overheating and wetting. The insufficient melting at the outline contour combined with good wetting of Zn liquid metal further increased the surface roughness and processing pores.

Temperature-dependent optical material properties of polymer powders regarding in-situ measurement techniques in additive manufacturing

Due to the growing number of applications for Additive Manufacturing (AM), an increasing need for enhanced quality control methods exists. Here optical measurement techniques are often used for in-situ monitoring in AM. There is a great potential to standardize and improve applications of optical measurement devices in accordance to the increasing requirements of measuring tasks. Beside the optical material qualifications, especially process-oriented changes in optical effects are of great relevance for in-situ evaluations. The optical modifications may be attributed to aggregate specific phase transitions coming along with variable emitted wavelengths. A measuring setup with two integrations spheres and a heated process chamber have been developed to analyze the optical interactions of laser radiation and visual illumination with the powder. The process oriented analysis for selective laser sintering lead to improved operating conditions in the field of in-situ measurements in combination with an accurate evaluation of the absorption ratio of the examined powder.

Spectroscopic Study on the Intermediates and Reaction Rates in the Oxidation of Levitated Droplets of Energetic Ionic Liquids by Nitrogen Dioxide.

To optimize the performance of hypergolic, ionic-liquid-based fuels, it is critical to understand the fundamental reaction mechanisms of ionic liquids (ILs) with the oxidizers. We consequently explored the reactions between a single levitated droplet of 1-butyl-3-methylimidazolium dicyanamide ([BMIM][DCA]), with and without hydrogen-capped boron nanoparticles, and the oxidizer nitrogen dioxide (NO2). The apparatus consists of an ultrasonic levitator enclosed within a pressure-compatible process chamber interfaced to complementary Fourier-transform infrared (FTIR), Raman, and ultraviolet-visible spectroscopic probes. First, the vibrational modes for the Raman and FTIR spectra of unreacted [BMIM][DCA] are assigned. We subsequently investigated the new structure in the infrared and Raman spectra produced by the reaction of the IL with the oxidizer. The newly produced peaks are consistent with the formation of the functional groups of organic nitro-compounds including the organic nitrites (RONO), nitroamines (RR'NNO2), aromatic nitro-compounds (ArNO2), and carbonitrates (RR'C═NO2-), which suggests that the nitrogen or oxygen atom of the nitrogen dioxide reactant bonds to a carbon or nitrogen atom of [BMIM][DCA]. Comparison of the rate constants for the oxidation of pure and boron-doped [BMIM][DCA] at 300 K shows that the boron-doping reduces the reaction rate by a factor of approximately 2. These results are compared to the oxidation processes of 1-methyl-4-amino-1,2,4-triazolium dicyanamide ([MAT][DCA]) with nitrogen dioxide (NO2) studied previously in our laboratory revealing that [BMIM][DCA] oxidizes faster than [MAT][DCA] by a factor of about 20. The present measurements are the first studies on the reaction rates for the oxidation of levitated ionic-liquid droplets.

Easy-to-use detection method for micro-arc discharge in plasma etching equipment by measuring current flowing to ground

A simple monitoring method for micro-arc discharge in plasma etching process has been developed. This method employs a current transformer, a Rogowski coil, which is externally attached to encircle a ground lead of a process chamber in plasma etching equipment without touching the lead. The results in this study demonstrate that this method can monitor the current flowing to ground, which reflects load current, and can detect micro-arc discharge occurring in plasma etching process. This easy-to-use, noncontact, and inexpensive method can contribute to improving the overall equipment effectiveness and the production yield in the wafer process in the mass production of LSI.

(Invited) The Mechanism of Surface Modifications of Photoresist Material in Plasma Etching Nano Processes

Etching plasmas employed for the fabrication of ultra large scale integrated circuits (ULSIs) have been causing serious damages to photoresist materials such as surface roughness formations and structural changes. So far, there have been many reports on suppressing these damages by some process techniques such as the UV, HBr plasma cure and so on. However, effects of individual species and photons in the plasma on the damages of photoresist materials have not been clarified enough. Especially, the effect of vacuum ultraviolet (VUV) photons on damages have never been quantitatively understood. Furthermore, beside the VUV photons, the synergetic effects of individual species of ion and radicals enhance the damages. As a result, the chemical structure alteration and the surface roughness formation of polymer materials are considered to be brought about. In the fabrication of the sub-45 nm devices and integrated circuits, it is extremely important to clarify the reaction mechanism of surface modification of photoresist materials induced by the plasma etching process. In this article, firstly, we have focused on the effects of VUV photons on damages on the 193 ArF photoresist materials by investigating the absolute density of VUV photon fluxes measured in the range of 115nm and 200nm in HBr plasma etching processes. The etching and measurement of VUV photons in the plasma were performed in the plasma beam system for understanding the fundamental reaction on the photoresists. This plasma beam system consists of an upper chamber (plasma chamber) and a lower chamber (process chamber). This equipment provided the beam source with the HBr plasma. The plasma beam system was pumped down to a base pressure of 10-5 Pa prior to the experiment. During the whole experiment, inductively coupled plasma (ICP) was generated by applying a radio-frequency (13.56 MHz) power of 400 W to the low-impedance antenna. Pure HBr, H2 or Ar gas was introduced into the plasma chamber at a flow rate of 1 sccm. The pressure of the plasma chamber was maintained at approximately 5 Pa. The chemical compositions of the surface of photoresists before and after the plasma beam irradiation were analyzed by in-situ XPS. On the basis of measured results, effects by VUV photons emitted from HBr on the surface modifications of photoresist materials were clarified. The VUV photons cleaved the MAA groups below the photon dosage of 16 × 1016 photons/cm2. The crosslinking of the photoresist and release of volatile products simultaneously generated the surface roughness. The reaction became saturated with high dosages [1]. Secondary, the sequential irradiation by VUV/radicals from HBr or H2 plasma and Ar ions on a photoresist have been performed. The irradiation by VUV and radicals before the ion irradiation (pre-treatment) suppressed the roughness increase by the ion bombardment but the VUV and radical irradiation after the ion irradiation (post-treatment) increased the roughness. The surface morphologies were also analyzed in detail after pre- or post-treatment on the photoresist by using the power spectral density. Such pre-treatment processes generated a dense and hard crosslinked layers which improved the etch resistance of the photoresist and improved the roughness [2]. The enhancement of roughness by post-treatment was correlated with the removal of the MAA groups and the nonuniformity of crosslinking reactions on the roughened photoresist by the ion irradiation. On the basis of these results, the mechanism of photoresist modifications by individual effects of VUV, ions and radicals and their synergetic effects by sequential irradiation experiments were systematically discussed and then perspectives for the damage less processes to be established in the etching nano processes are introduced. [1] Y. Zhang et al., Journal of Vacuum Science & Technology A, 35, 060606 (2017). [2] Y. Zhang et al., Japanese Journal of Applied Physics, 56, 126503 (2017).

A novel method of quantifying the coating progress in a three-dimensional prismatic spouted bed

An optical method of experimentally quantifying the coating progress in a laboratory prismatic spouted bed is presented. Microcrystalline cellulose particles with size dp=0.57mm are used as core material. Waterborne coating suspensions with methylene blue as a dye are used and sprayed via a two-fluid nozzle in bottom-spray configuration. A high-speed camera with a color filter is positioned in front of the observation window of the three-dimensional plant and records the flow pattern in the process chamber with a certain frequency. With increasing surface coverage, the particles become bluer and darker. The change in brightness is detected by digital image analysis. In the implemented algorithm, the spherical particles are detected, cut from the background and normalized regarding their lighting and area. The detection of coated pixels on the single particles allows the calculation of the coating fraction and coating uniformity after a Kalman filter has been applied to reduce noise. It is shown that the method can be used to determine the time needed to reach the maximum blue value indicating a complete coating of the particle bed. Besides the minimum coating duration, information on the spraying performance (e.g., the time point of a possibly occurring blockage of the nozzle) can be obtained from the data. Two exemplary experiments are presented, showing a connection of the slope of the coating fraction and the uniformity of the coating of the particles in the apparatus that results in the recommendation of a slow liquid injection for obtaining consistent coating layers as desired in many applications.

Multitask learning for virtual metrology in semiconductor manufacturing systems

Abstract Virtual metrology (VM) estimates the real metrology of wafers from process data collected from multiple chambers. In semiconductor manufacturing, independent models for each process chamber are limited because the number of sampled wafers measured at each chamber are too few to build a reliable model. One potential solution to this problem is to pool the data from all chambers to create a model capable of learning and serving as a global predictive model. However, even with chambers that perform the same operation, the condition of their semiconductor tools may vary because of various factors. This study uses, for the first time, various multitask methods to develop VM models. By learning multiple related tasks simultaneously, multitask methods effectively increase the number of observations included in the prediction model. In addition, by identifying the related task, the method can make a prediction using only similar tasks. This property of multitask learning can be useful to account for lack of information in a single chamber and for diversity among the chambers. The experimental results indicate that multitask models consistently outperformed independent and pooled models regardless of the size of the training set used. Among the multitask methods, a multitask tree-based ensemble model outperformed the others in every case. This implies that the problem of wafer quality prediction can be better addressed with a form of multitask learning.

Microwave-freeze drying of lactic acid bacteria: Influence of process parameters on drying behavior and viability

Abstract Microwave-freeze drying was investigated as an alternative to conventional lyophilization to preserve the lactic acid bacteria Lactobacillus paracasei ssp. paracasei F19 (Lb. paracasei) and Bifidobacterium animalis ssp. lactis INL1 (B. lactis). The process parameters microwave power input (1.5–3 W∗g−1) and chamber pressure (0.6, 1, 2 mbar) were varied. Drying kinetics, overall drying time, process stability and energy demand were assessed. Survival rate and cell membrane integrity were evaluated. Survival rate and membrane integrity after microwave-freeze drying were comparable to the standard lyophilization process for both cultures. For Lb. paracasei, survival could almost be maintained at all microwave-freeze drying process conditions. Best results in terms of process stability were achieved at 1 mbar and 1.5 W∗g−1. For B. lactis, the highest survival of more than 90% was measured at 0.6 mbar and 1.5 W∗g−1 microwave input. These conditions led to a drying time of 5 h, whereas conventional freeze drying lasted 24 h. A potential reduction of drying time compared to freeze drying of bacterial cultures of up to 80% renders microwave-freeze drying an alternative with comparable survival rates but higher efficiency.

Miniature Fuel Cell with Monolithically Fabricated Si Electrodes - Application of a Polymer Electrolyte Membrane with Adapted Shape

Miniature fuel cells have attracted attention as an ultimate portable power source, and we have developed monolithically fabricated Si electrodes for the miniature fuel cells [1]. In the fuel cells, two Si electrodes with porous Pt catalyst layer are pressed onto either side of a PEM (polymer electrolyte membrane) , and the prototype fuel cells showed promising performances of over 500mW/cm2 output at 313K with H2-O2. However, the high output was obtained with only 1 mm2 reaction area. Along with enhancement of the reaction area, the performance dropped. We assumed that the performance drop is caused by poor adhesion between Si electrodes, because the porous Pt layer becomes depressed several micrometers from the substrate surface during the formation process using anodized porous Si and voids appears at interface between electrodes and PEMs as shown in figure 1(a). In this study, we attempted to adapt PEM shape to the depression of the porous Pt catalyst layer as shown in figure 1(b). Generally, swelling of PEM caused serious damages to miniature fuel cells because of their fragile nature of porous-Pt and we have employed pore-filling membranes to avoid the swelling in our fuel cells. The pore-filling membrane has two components: a porous polymer substrate to provide mechanical strength and an electrolyte polymer in the pores for proton conductivity. In order to machine the PEM to fit the depression, we decided to apply O2 plasma etching to the porous polymer substrate and fill electrolyte polymer into the substrate after the shaping, because damage to electrolyte with long O2 plasma irradiation was a concern. To protect the central area of the porous polymer substrate from the plasma, circular copper plate was used as a mask and was put on the substrate in the process chamber. Plasma etching was applied on both side of the substrate. Figure 2 shows the porous polymer membrane after the plasma etching. As we expected, the substrate has circular thick area. Gas permeability of the porous polymer substrate did not change even after the several micrometers etching, and it was assumed that porous structure was maintained at plasma irradiated area. After the shaping, 2-acrylamido-2-methylpropan sulfonic acid (AMPS) was filled in to the substrate and the monomer was polymerized by heating [2]. Prototype cells with 4mm2 reaction area with the proposed adapted shape PEM and conventional flat PEM were made and power generation tests were performed. With the adapted shape PEM prototypes, 780 mW/cm2 at average and max. of 1050 mW/cm2 outputs were obtained, which is the best among our results. While with conventional PEMs, average output was 320 mW/cm2 and even maximum was 420 mW/cm2.

Fabrication of Ta2O5 Reinforced Ta-based Coatings on Ta Substrates by Laser Cladding

Tantalum (Ta) is a remarkable biological substance, with excellent corrosion resistance and biocompatibility. However, pure Ta coatings do not possess sufficiently high mechanical properties, especially wear resistance. To improve the wear resistance of Ta, Ta2O5 reinforced Ta-based coatings were fabricated on Ta substrates using laser cladding with a direct pre-placed powder method. The microstructure of the coating was primarily the result of a monotectic reaction and can be interpreted using the Ta-O phase diagram. The results suggested that Ta-Ta2O5 graded coatings can be fabricated on Ta substrates by controlling the amount of melting of the Ta substrate and/or adjusting the oxygen level of the processing chamber during laser cladding. The corrosion and wear resistances of the composite coating were higher than those of the uncoated Ta material when free corrosion potential, corrosion current density and wear track width were considered.

Scheduling Single-Armed Cluster Tools With Chamber Cleaning Operations

Circuit widths and nodes of semiconductor wafers have been continually shrinking down to less than 20 nm. Therefore, modern wafer fabs enforce extremely strict process control to prevent wafer quality failures. A wafer processing chamber is now frequently cleaned to remove residual chemicals and impurities. Yu et al. show that such cleaning operations significantly change the tool operation of single-armed cluster tools, and they suggest an idea of partial wafer loading to improve the tool throughput under cleaning requirements. However, little is known about how a dual-armed tool could be effectively scheduled when chamber cleaning exists. A dual-armed robot allows more flexible tool operational sequences, and hence, the scheduling problem becomes further complicated and challenging. In this paper, we propose a scheduling method by which the dual arms can be properly exploited for better tool productivity. We show that the suggested hybrid sequence significantly reduces the tool cycle time as compared to previously developed scheduling methods. Through this research, we conclude that the productivity gain of the dual arms against single arm is more significant when chambers are cleaned. Note to Practitioners —This paper is motivated by the scheduling issues of cluster tools with chamber cleaning requirements. Though an efficient scheduling method for single-armed cluster tools is presented by Yu et al. , its performance is not sufficiently close to the optimal when a dual-armed robot is considered. More specifically, we cannot expect any productivity improvement from adopting a dual-armed robot, although it allows more flexible tool operations and is known to have higher throughput than a single-armed robot. Thus, we propose a novel scheduling method for dual-armed cluster tools that require chamber cleaning operations. The experimental results show that the suggested method achieves optimal tool throughput in most of the practical tool conditions.

Chemical Vapour Deposition of Hexagonal Boron Nitride for Two Dimensional Electronics

Hexagonal boron nitride (h-BN) has potential applications in protective coatings, single photon emitters and as substrate for graphene electronics. In this paper, we report on the growth of h-BN by chemical vapor deposition (CVD) using ammonia borane as the precursor. Use of CVD allows controlled synthesis over large areas defined by process parameters, e.g. temperature, time, process chamber pressure and gas partial pressures. Furthermore, independently grown graphene and h-BN layers are put together to realize enhancement in electronic properties of graphene.

Modification of Physico-Chemical Properties of Acryl-Coated Polypropylene Foils for Food Packaging by Reactive Particles from Oxygen Plasma

This investigation was focused on the influence of long-living neutral reactive oxygen species on the physico-chemical properties of acryl-coated polypropylene foils for food packaging. Reactive species were formed by passing molecular oxygen through a microwave discharge and leaking it to a processing chamber of a volume of 30 L, which was pumped by a rotary pump. The density of neutral O-atoms in the chamber was tuned by adjustment of both the effective pumping speed and the oxygen leak rate. The O-atom density was measured with a catalytic probe and was between 3 × 1018 and 5 × 1019 m−3. Commercial foils of biaxially oriented polypropylene (BOPP) coated with acrylic/ poly(vinylidene chloride) (AcPVDC) were mounted in the chamber and treated at room temperature by O atoms at various conditions, with the fluence between 1 × 1021 and 3 × 1024 m−2. The evolution of the surface wettability versus the fluence was determined by water contact angle (WCA) measurements, the formation of functional groups by X-ray photoelectron spectroscopy (XPS), and the morphology by atomic force microscopy (AFM). The WCA dropped from the initial 75° to approximately 40° after the fluence of a few 1022 m−2 and remained unchanged thereafter, except for fluences above 1024 m−2, where the WCA dropped to approximately 30°. XPS and AFM results allowed for drawing correlations between the wettability, surface composition, and morphology.

Petri Net Modeling and Scheduling of a Close-Down Process for Time-Constrained Single-Arm Cluster Tools

In wafer fabrication, a robotic cluster tool is required to be closed down in order for engineers to perform its on-demand and preventive maintenance and switch between different wafer lots. They often deal with a close-down process subject to wafer residency time constraints, i.e., a wafer must exit from a processing chamber before its quality degradation within a certain time limit. To obtain higher yield, it is very important to optimize a close-down process for a cluster tool. Yet the existing literature pays no or little attention to this issue. By focusing on a time-constrained single-arm cluster tool, this paper intends: 1) to build its Petri net model to analyze its schedulability and 2) to develop computationally efficient algorithms to find an optimal and feasible schedule for its closing-down process under different workloads at its steps. Industrial examples are used to illustrate the application of the proposed method.

Real-time plasma monitoring technique using incident-angle-dependent optical emission spectroscopy for computer-integrated manufacturing

Abstract Although various monitoring techniques are currently used for semiconductor manufacturing, OES is a non-contact and non-destructive plasma measurement tool that detects end points and plasma abnormality. Despite these advantages and their high utilization in plasma processing measurement, the acquisition region of OES data at various wafer sizes only allows examination of part of the plasma, owing to the characteristics of the conventional OES resulting in the limited detection capability of process abnormality. In this paper, a novel real-time monitoring method for detecting plasma process uniformity and abnormality using incident-angle-dependent OES is proposed. Using both a body tube and a wide-angle lens to adjust the incident angle of OES, the intensity of plasma light can be measured accurately using selective plasma light in semiconductor manufacturing. This real-time monitoring technique can be utilized to obtain plasma light in a process chamber and thereby analyze the uniformity and detect the abnormalities in the plasma process for computer-integrated manufacturing.

Effect of postharvest UV-C treatment on the microbial quality of ‘Şalak’ apricot

Abstract Inactivation of natural flora found on cv. ‘Salak’ apricot surfaces was investigated using a newly designed UV-C treatment system equipped with four UV lamps and a rotating roller bearing. Multiple Point Source Summation (MPSS) Model was used to estimate UV light intensity field in this processing chamber. Although MPSS model over-predicted the UV intensity data, light intensity profile showed a good agreement with the radiometric measurements. UV-C treatment of apricots resulted in 3-log reduction in the number of total mesophilic aerobic bacteria (TAPC) at 32.3 W m−2 of average UV light intensity for 16 min at 31.01 kJ m−2 of UV dose whereas 2.38-log reduction was achieved for yeast and mould count (YMC) after 4 min of UV exposure at 7.75 kJ m−2 of UV dose. On the other hand, complete inactivation of coliform bacteria was observed after all treatments. Statistical analysis indicated that further extension of the exposure time did not cause any significant effect on the inactivation of natural flora of apricot surfaces. Additionally, the inactivation data obtained for TAPC and YMC were modelled by using log-linear regression, Biphasic model, log-linear + tail, Weibull model, Weibull + tail, double Weibull and biphasic + shoulder models. The inactivation kinetics of TAPC and YMC were best described by log linear + tail model with the smallest root mean squared error (RMSE) and the highest regression coefficient (R2 > 0.90). These results suggest that UV-C treatment can be applied to control the natural flora on cv. ‘Salak’ apricots. Use of a rotating roller bearing is highly appreciated in UV-C systems to provide equal radiation among fruit surfaces.

Virtual prototype of a low-cost vacuum baffle based on thermoelectric cooling

Contaminants can enter vacuum systems from two main sources: backstreaming of oil vapors from the diffusion and mechanical pumps, and vapors generated as byproducts in the process chamber. Both sources can be hindered by using an appropriate baffle.We developed a virtual prototype of a low-cost baffle for vacuum systems that is cooled down with thermoelectric coolers (TECs). Compared to compressor cooling systems, TECs have useful advantages for this application: they are compact, silent, vibration-free, almost maintenance-free, inexpensive, widely commercially available, and capable of providing a precise temperature control. The baffle is partly built inside a tee vacuum fitting. A refrigerated cooper helix provides the trapping surfaces for contaminants flowing between the process chamber and the vacuum pumps. The cost of the baffle is below USD 250.The proof-of-concept model, implemented by the finite element method, showed that, when using TEC1-12706 modules, the helix can reach temperatures as low as −50 °C. According to our analysis, this temperature is more than enough for trapping the contaminants described above.

Scaling of massively parallel patient-specific cell cultures with a transportable conditioned cell culture chamber

Barrier Isolators, which separate the cell culture processing atmosphere from the bioburden introduced by personnel, can reduce contamination risks to a cell or tissue product. Compared to open clean room processing, isolator modules can be more readily replicated to scale-up operations. However, for processing of massively parallel patient-specific cell cultures, incubation capacity in a barrier isolator can be a bottleneck. Flexible incubation capacity can be provided by external incubators if cultures can be safely transported to and from the isolator for processing. We tested a transportable conditioned cell culture chamber (TC4) designed for this purpose. We previously published on good cell growth using this processing system to expand K562. In this study, we performed mock production runs with a highly permissive color-changing bacterial broth. We took samples of the final mock cell product and incubated them for bacterial growth. We also performed environmental monitoring of the cell processing chamber with an air sampler and contact plates. Positive control samples were all yellow and turbid. Negative samples and all test materials were negative for microbial growth. We concluded that this transport chamber could safely alleviate the bottleneck in cell production presented by the needs of massively-parallel patient specific cell incubation.

Development of Minimal Si-DRIE Tool and Process Performance

The expertise of SPP Technologies in plasma processing techniques has led to the company`s cooperation in the “minimal fab” concept proposed by AIST. A Bosch process deep silicon reactive ion etching process chamber has been developed. A plasma with similar properties to those generated in a mass-production process chamber has been realized in a minimal fab process chamber. Design and evaluation of the minimal process chamber was performed by plasma and radical characterization. Successful process results were achieved by generating a plasma with similar density and bias energy to that of a mass production chamber. SPP Technologies has achieved the first Si-DRIE minimal process chamber using the Bosch process. SPT's Minimal Si-DRIE chamber, a research platform aimed at IoT, AI, and other MEMS devices, can be expected to make a big impact due to its early release.