Silicon Nitride Films Research Articles

Development of silicon nitride-based nanocomposites with multicolour photoluminescence

Silicon-rich nitride nanocomposites with stable multicolour photoluminescence (PL) are developed in this work. Firstly, a single PL band can be adjusted in the visible spectral range. Secondly, simultaneous emission of an additional PL band is achieved due to boron-doping of the nanocomposites. Impact of thermal annealing of the silicon nitride films in different atmospheres at various temperatures on their PL spectra is studied. Processes responsible for multicolour emission in the boron-doped nanocomposites are discussed. The developed nanocomposites can be further applied for nanothermometry or biosensing applications. They can be also used for synthesis of silicon nanoparticles with multicolour PL. Intense violet-based multicolour photoluminescence of silicon nitride nanocomposite with tunable emission position is achieved.

Surface modification of Ti64-Alloy with silver silicon nitride thin films

Ti6Al4V (Ti64) alloys is an alpha-beta titanium alloy with good corrosion resistance, high strength-to-weight ratio, excellent physiochemical stability and good biocompatibility. However, Ti64 alloy loses its biocompatibility when it is introduced into human tissues due to possible toxic of Vanadium (V) and Aluminum (Al) ion release. Thus, modification using silver silicon nitride films onto Ti64 via magnetron sputtering technique was proposed. In this study, a set of experimental depositing AgSiN films on Ti64 alloys using different bias voltage (0, −75, −150 and −200 V) were fabricated. The surface characterization and mechanical performance of the thin films with respect to bias voltage were studied using scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), nanoindentation and scratch test. Meanwhile, the biological function of the films was tested through wettability and antibacterial tests. According to the results, all thin films showed similar morphology with the highest adhesion strength (596 mN) was obtained for AgSiN thin film deposited at −75 V. The hardness (5.5 GPa) and elastic modulus (211.0 GPa) of sample deposited at −150 V showed an improvement for about 50% compared to the Ti64 substrate (H = 2.75, E = 113.8). The lowest compressive residual stress 0.06 GPa was noted for samples that have highest adhesion strength and highest thickness. In terms of biological functionality, all films showed hydrophilic property with wetting angle observed were below 90°. An inhibition zone area that observed on Bulkholderia pseudomallei (B.Psudomallei) and Escherichia coli (E.coli) were 7 and 10 mm respectively, which proved the AgSiN films as a promising candidate to be used in antibacterial applications.

Broadband extreme ultraviolet dispersion measurements using a high-harmonic source.

We demonstrate direct dispersion measurements of various thin films at extreme ultraviolet (EUV) wavelengths, using a table-top laser-driven high-harmonic generation (HHG) source. In this method, spatially separated identical EUV pulses are generated through HHG with a pair of phase-locked infrared pulses. The EUV pulses are re-imaged to a sample plane using a single toroidal mirror, such that one pulse illuminates the target thin film, while the other pulse passes through a reference aperture. By comparing the EUV interference with and without a sample, we are able to extract the dispersion properties of the sample, integrated over the full film thickness. We have measured thin films of titanium, nickel, copper, and silicon nitride, demonstrating that this technique can be applied to a wide range of materials, only requiring a film thin, enough for sufficient EUV transmission.

Negatively charged silicon nitride films for improved p-type silicon surface passivation by low-temperature rapid thermal annealing

The effect of post-deposition rapid thermal annealing (RTA) on p-type Czochralski silicon surface passivation by plasma-enhanced chemical vapor deposited nitrogen-rich silicon nitride (SiNx) films has been investigated. The effective carrier lifetime is significantly improved after annealing at low temperature (400 °C–450 °C) for 15–30 s. This improvement is associated with a decrease of N–H and Si–H bond densities in SiNx films and, a resultant decreased density of states at the SiNx/Si interface. More importantly, the polarity of fixed charges is converted from positive to negative in the annealed SiNx films. It is demonstrated that a release of hydrogen atoms to the SiNx/Si interface combined with a tuning of charges during low-temperature RTA, is very beneficial for p-type silicon surface passivation.

Optical Characterization of Non-Stoichiometric Silicon Nitride Films Exhibiting Combined Defects

The study was devoted to optical characterization of non-stoichiometric silicon nitride films prepared by reactive magnetron sputtering in argon-nitrogen atmosphere onto cold (unheated) substrates. It was found that these films exhibit the combination of three defects: optical inhomogeneity (refractive index profile across the films), uniaxial anisotropy with the optical axis perpendicular to the boundaries and random roughness of the upper boundaries. The influence of the uniaxial anisotropy was included into the corresponding formulae of the optical quantities using the matrix formalism and the approximation of the inhomogeneous layer by a multilayer system consisting of large number thin homogeneous layers. The random roughness was described using the scalar diffraction theory. The processing of the experimental data was performed using the multi-sample modification of the least-squares method, in which experimental data of several samples differing in thickness were processed simultaneously. The dielectric response of the silicon nitride films was modeled using the modification of the universal dispersion model, which takes into account absorption processes corresponding to valence-to-conduction band electron transitions, excitonic effects and Urbach tail. The spectroscopic reflectometric and ellipsometric measurements were supplemented by measuring the uniformity of the samples using imaging spectroscopic reflectometry.

Silicon nitride/titanium oxide hybrid waveguide design enabling broadband athermal operation

This paper presents a special design of a new kind of silicon nitride/titanium oxide hybrid waveguide with multi-layer materials laminate structure aiming at broadband athermal operation. By incorporating three layers of titanium oxide whose thermo-optic coefficient (TOC) is negative in the waveguide core and upper cladding regions, the thermal drift of the conventional strip waveguide induced by the positive TOC of silicon nitride is fully compensated, with the effective TOC of the hybrid waveguide achieving zero at 1550nm and only varying extremely slightly within ±6×10-7/K in the wavelength band from 1350 to 1850nm. In addition, due to the inherent alternate growth manner of titanium dioxide and silicon nitride thin layers, this new kind of multi-layer material laminate structure waveguide holds the potential of avoiding the challenging growth of low-stress crack-free single-layer silicon nitride film thick enough for realizing an anomalous dispersion waveguide. Furthermore, we numerically demonstrate the different influences of the temperature change on optical frequency comb generation between the traditional waveguide and the hybrid waveguide, and we find that the athermal hybrid waveguide is much more temperature insensitive than the strip waveguide.

Effect of thermal and pulse laser annealing on photoluminescence of CVD silicon nitride films

The light-emitting properties of Si-rich silicon nitride films deposited on the Si (100) substrate by plasma-enhanced (PECVD) and low-pressure chemical vapor deposition (LPCVD) have been investigated. In spite of the similar stoichiometry (SiN1.1), nitride films fabricated by different techniques emit in different spectral ranges. Photoluminescence (PL) maxima lay in red (640 nm) and blue (470 nm) spectral range for the PECVD and LPCVD SiN1.1 films, respectively. It has been shown that equilibrium furnace annealing and laser annealing by ruby laser (694 nm, 70 ns) affect PL spectra of PECVD and LPCVD SiN1.1 in a different way. Furnace annealing at 600 °C results in a significant increase of the PL intensity of the PECVD film, while annealing of LPCVD films result only in PL quenching. It has been concluded that laser annealing is not appropriate for the PECVD film. The dominated red band in the PL spectrum of the PECVD film monotonically decreases with increasing an energy density of laser pulses from 0.45 to 1.4 J/cm2. Besides, the ablation of PECVD nitride films is observed after irradiation by laser pulses with an energy density of > 1 J/cm2. This effect is accompanied by an increase in blue emission attributed to the formation of a polysilicon layer under the nitride film. In contrast, the LPCVD film demonstrates the high stability to pulsed laser exposure. Besides, an increase in the PL intensity for LPCVD films is observed after irradiation by a double laser pulse (1.4 + 2 J/cm2) which has not been achieved by furnace annealing.

A Highly Robust Silicon Ultraviolet Selective Radiation Sensor Using Differential Spectral Response Method.

This paper presents a silicon ultraviolet radiation sensor with over 90% UV internal quantum efficiency (QE) and high selectivity to the UV waveband without using optical filters. The sensor was developed for applications that require UV measurement under strong background visible and near-infrared (NIR) lights, such as solar UV measurement, UV-C monitoring in greenhouses or automated factories, and so on. The developed sensor is composed of monolithically formed silicon photodiodes with different spectral sensitivities: a highly UV responsive photodiode with internal quantum efficiency (QE) of nearly 100% for UV light, and a lowly UV responsive photodiode with UV internal QE lower than 10%. The photodiodes were optimized to match their visible and NIR light responsivity, and the UV signal is extracted from the background radiation by using the differential spectral response method. With this approach, an internal QE of over 90% for UV light was obtained, with a residual internal QE to non-UV light lower than 20% for 400 nm, 5% for 500 nm, 2% for 600 nm and 0.6% to NIR light. The developed sensor showed no responsivity degradation after exposure towards strong UV light. It was confirmed by the simulation results that the residual responsivity is further suppressed by employing an on-chip band-rejection optical layer consisting of several layers of silicon oxide and silicon nitride films.

The influence of dielectric layer on the thermal boundary resistance of GaN‐on‐diamond substrate

The cooling behavior of GaN‐on‐diamond substrate can be enhanced by reducing the thermal boundary resistance (TBR), which is mainly determined by the nature of interlayer. Although SiN film is considered as the primary candidate of dielectric layer, it is still needed to be optimized. In order to facilitate the understanding of the influence of dielectric layer on the TBR of GaN‐on‐Diamond substrate, aluminum nitride (AlN), and silicon nitride (SiN) film were compared systematically, both of which are 100 nm. The time‐domain thermoreflectance (TDTR) measurements, adhesion evaluation, and microstructural analysis methods were adopted to analyse these two interlayers. The results show the TBR of SiN interlayer is as low as 38.5 ± 2.4 m2K GW−1, comparing with the value of 56.4 ± 5.5 m2K GW−1 for AlN interlayer. The difference of TBR between these two interlayers is elucidated by the diamond nucleation density, and the adhesion between the diamond film and GaN substrate, both of which are affected by the surface charge and chemical groups of the dielectric layer.

69‐1: Etch Properties of Silicon Nitride Films Using a New In‐Line Equipment with Atmospheric Glow Plasma for the OLED Flexible Display

DBD non‐thermal atmospheric pressure plasma (NAPP) is suitable for the OLED display manufacturing process using flexible substrate because it is low‐temperature atmospheric pressure process, low cost process and does not need a vacuum system. High dynamic etch rate of 220À·cm/s in Si3N4 thin films was obtained in flow rate ratio (O2/CF4) of 0.13, rf 480W, the speed of 10mm/s in a 200mm new inline NAPP system. About 5% increase of dynamic etch rate by N2 gas injection was conformed. Etch profile of Si3N4 film with patterned PR shows perfectly isotropic without undercut because the species such as CF3, COF2, F and O have low energy and chemical reaction.

Microstructure and Mechanical Property Investigation of TaSiN Thin Films Deposited by Reactive Magnetron Sputtering

Tantalum silicon nitride (Ta–Si–N) films were synthesized on Si substrate via magnetron sputtering. The structure and properties of the Ta–Si–N films were investigated as a function of the N2 content in the N2/Ar gas mixture. Increasing the N2 percentage in the gas mixture from 7% to 20% changed the film structure from textured hexagonal (hex) Ta2N to nontextured hex Ta2N to a mixture of face-centered cubic (fcc) TaN and hex Ta2N, and finally to fcc TaN. X-ray photoelectron spectroscopy showed Ta–N and Si–N bonds in the films. The film microstructure was found to change from columnar morphology with visible amorphous boundaries (at 13% N2) to columnar morphology with absence of amorphous boundaries (at 15% N2). Increasing N2 content increased hardness in the films with those deposited with 13–15% N2 displaying the highest hardness of ~40 ± 2 GPa. In addition, the 13% N2 films showed a ratio of H/E* > 0.11, elastic recovery of ~60%, low coefficient of friction of 0.6, reduced wear rate (7.09 × 10−6 mm3/N·m), and remained thermally stable up to 800 °C. The results suggest that the Ta–Si–N films have high potential as hard tribological nanocomposite coatings.

PECVD grown silicon nitride ultra-thin films for CNTFETs

As-fabricated carbon nanotube field effect transistors (CNTFETs) exhibit p-type nature. In this work, silicon nitride (SiNx) films are deposited on CNTs to realize n-type CNTFETs. This method of fabricating n-type CNTFETs is advantageous as SiNx film serves both as a passivation layer and as a top-gate dielectric. There has been extensive work done on SiNx passivation phenomena previously, but very few have investigated the properties of ultra-thin SiNx films with thickness less than 20 nm. In this work, the ultra-thin SiNx films are deposited using plasma enhanced chemical vapor deposition (PECVD) method. This paper discusses the systematic investigation of the effect of PECVD process parameters such as flow rates of precursor gasses (NH3, SiH4), power of electrodes and deposition temperature on the properties of SiNx films such as refractive index, dielectric constant and stoichiometry. The quality of the SiNx thin films obtained is comparable with several reports that have investigated thicker films. Using these ultra-thin SiNx films, we implement a CNTFET based logic inverter. The results indicate that ultra-thin films of SiNx have great potential in future transistor technology.

Calcium phosphate mineralization in bone tissues directly observed in aqueous liquid by atmospheric SEM (ASEM) without staining: microfluidics crystallization chamber and immuno-EM

The malformation and disordered remodeling of bones induce various diseases, including osteoporosis. We have developed atmospheric SEM (ASEM) to directly observe aldehyde-fixed bone tissue immersed in radical scavenger buffer without thin sectioning. The short procedure realized the observation of bone mineralization surrounded by many cells and matrices in natural aqueous buffer, decreasing the risk of changes. In osteoblast primary cultures, mineralization was visible without staining. Correlative energy dispersive X-ray spectrometry indicated the formation of calcium phosphate mineral. Fixed bone was sectioned, and the section surface was inspected by ASEM. Mineralized trabeculae of talus spongy bone were directly visible. Associated large and small cells were revealed by phosphotungstic acid staining, suggesting remodeling by bone-absorbing osteoclasts and bone-rebuilding osteoblasts. In tibia, cortical bone layer including dense grains, was bordered by many cells with protrusions. Tissue immuno-EM performed in solution for the first time and anti-cathepsin-K antibody, successfully identified osteoclasts in femur spongy bone. A microfluidics chamber fabricated on the silicon nitride film window of an ASEM dish allowed mineralization to be monitored in vitro; calcium phosphate crystals as small as 50 nm were imaged. ASEM is expected to be widely applied to study bio-mineralization and bone-remodeling, and to help diagnose bone-related diseases.

SiNx Deposition at Low Temperature Using UV-Irradiated NH3

Introduction Technology for depositing silicon nitride (SiNx) films at low temperature has been extensively studied. Plasma-enhanced chemical vapor deposition and photo-chemical vapor deposition can deposit SiNx films at low temperature (1-3). However, a substrate exposed to plasma or UV light is damaged (4). Deposition equipment with low plasma damage has also been developed (1-2); however, such damage is difficult to avoid. In this paper, we suggest a low-temperature SiNx film deposition technique that does not cause plasma or UV damage. Further, we deposited SiNx film to evaluate its characteristics. Experiment Fig. 1 shows a schematic diagram of the SiNx film deposition equipment. The equipment was constructed with a UV irradiation chamber and a tube reactor for SiNx film deposition. Ammonia (NH3) gas was excited by UV light and then supplied to the tube reactor. Si2H6 gas was directly supplied to the tube reactor without the UV irradiation. The UV light was emitted perpendicular to the NH3 flow in the UV irradiation chamber separate from the tube reactor and Si2H6. Because the UV light did not reach the substrate, the deposited films are not damaged and the film is not deposited the glass window for the irradiation chamber. The wavelength range of UV light of 160 – 210 nm included the absorption wavelength of NH3 (5). The deposition temperatures were 30˚C and 450˚C. We evaluated the effect of the UV-irradiated NH3 for the formation of high quality SiNx film. The nitrogen content of the films was analyzed by X-ray photoelectron spectroscopy (XPS). Result and discussions The effect of UV-irradiated NH3 is shown in Fig. 2. The vertical axes show the thickness and refractive index evaluated by ellipsometry. Horizontal axes indicates measurement positions shown in Fig. 1. NH3, N2 or H2 were supplied to the tube reactor with and without UV irradiation. A film having a refractive index near 2.0 was clearly deposited only when UV-irradiated NH3 was supplied. When N2 and H2 was supplied, regardless of the UV irradiation, almost the same films having thickness and refractive index were obtained. These results indicate that UV irradiation of N2 and H2 gas did not affect the reaction of not only N2 and H2, but also Si2H6. Fig. 3 shows composition ratio measured by XPS of the film deposited on the 300 nm thick SiO2. Figs. 3(a)-3(b) show that the film containing nitrogen was formed at 30°C and 450°C. The N/Si ratio of the film deposited at 450˚C with UV-irradiated was near 1.33, and the film’s depth profile had a region where no oxide was detected. These results show that the stoichiometric composition of the deposited film was close to Si3N4, and the film cannot be oxidized by the atmosphere of the clean room at R.T. Conclusion We suggested a low-temperature SiNx film deposition technique using UV-irradiated NH3 and demonstrated the deposition of SiNx films at low temperature. When UV-irradiated NH3 was used, nitrogen-containing film with an N/Si ratio close to 1.33 was clearly deposited at 450°C. In addition, the UV light introduced into the irradiation chamber excited only NH3 molecules, and it did not reach the substrate in the tube reactor. These results show that UV irradiation with NH3 is able to deposit SiNx films without UV damage at low temperature. Figure 1

Hollow Cathode Plasma (HCP) Enhanced Atomic Layer Deposition of Silicon Nitride (SiNx) Thin Films Using Pentachlorodisilane (PCDS)

Silicon nitride (SiNx) films have drawn great attention due to the wide range of applications such as passivation layer, gate dielectric, spacer, charge trap layer, and diffusion barrier [1]. Conventionally used LPCVD and PECVD for SiNx deposition have limitations in terms of conformal deposition and thickness scalability. Since plasma enhanced atomic layer deposition (PEALD) is expected to overcome these shortcomings, several research groups have reported SiNx film deposition. A number of studies on PEALD SiNx process using various chlorine-containing silicon precursors have been reported due to their ease in synthesis as well as good thermal stability [2]. Recently, PEALD SiNx film using a novel chlorosilane precursor, pentachlorodisilane (PCDS, HSi2Cl5) with NH3/N2 plasma was reported [3]. Under the NH3/N2 plasma condition, PCDS enhanced the growth rate (approximately > 20 %) compared to the hexachlorodisilane (HCDS, Si2Cl6), but still showed relatively poor wet etch resistance. Inspired the film characteristics, we propose to explore the feasibility of improving the wet etch resistance of PEALD-SiNx films using the different gas mixture for plasma. It has been reported that the wet etch rate of SiNx films has a linear relationship with the hydrogen concentration in the films [1]. Compared to NH3/N2 plasma, N2-H2 (forming gas) plasma improves the wet etch rate possibly due to less N-H and H-N-H bonds in the SiNx films [2]. Herein, PEALD SiNx films using PCDS as Si precursor and N2-H2 (10 % forming gas) plasma as the reactant were evaluated. The combination with PCDS and N2-H2 plasma showed a relatively lower (approximately < 10 %) growth rate than NH3/N2 plasma under a range of process temperatures (270−300 °C) whereas the wet etch resistance to HF acid was improved (> 1.5 nm/min, 500:1 HF). Studying these results, we suggest the effect of hydrogen on film properties such as growth rate, film composition, and wet etch resistance. [1] H.S. Kim, X. Meng, S.J. Kim, A.T. Lucero, L. Cheng, Y.C. Byun, J.S. Lee, S.M. Hwang, A.L.N. Kondusamy, R.M. Wallace, G. Goodman, A.S. Wan, M. Telgenhoff, B.K. Hwang, and J. Kim, ACS Appl. Mater. Interfaces 10, 44825 (2018). [2] X. Meng, Y.C. Byun, H.S. Kim, J.S. Lee, A.T. Lucero, L. Cheng, and J. Kim, Materials 9, 1007 (2016). [3] X. Meng, H.S. Kim, A.T. Lucero, S.M. Hwang, J.S. Lee, Y.C. Byun, J. Kim, B.K. Hwang, X. Zhou, J. Young, and M. Telgenhoff, ACS Appl. Mater. Interfaces 10, 14116 (2018). Figure 1

Flash Lamp Annealed Polycrystalline Silicon TFT Dependence on Surface Morphology and the Back-Channel Material Interface

This work studies the operation of polycrystalline silicon p-channel TFTs prepared via Flash Lamp Annealing (FLA). Silicon nitride was investigated as a back-channel interface layer to suppress void formation via dewetting of molten silicon. Predefined polygons of amorphous silicon were crystallized on display glass using single-pulse FLA exposure. Two distinct surface morphologies were realized within the same exposed region as a result of the underlying silicon nitride film and localized variation in the substrate thermal contact during PECVD deposition of amorphous silicon. While both resulting morphologies have polysilicon grains on micron scale, differences in TFT electrical behavior appear to coincide with differences in grain structure and boundary regions. The electrical results also indicate inferior electrical performance in response to the back-channel silicon nitride in comparison to results demonstrated on SiO2. Extracted parameters provide a quantitative assessment of the device operation as related to surface morphology and the back-channel material interface.

Synthesis and optimization of low-pressure chemical vapor deposition-silicon nitride coatings deposited from SiHCl3 and NH3

Stoichiometric silicon nitride films were deposited by low-pressure chemical vapor deposition from the SiHCl3-NH3-H2-Ar system in a hot wall reactor at pressures ranging from 0.3 to 2 kPa. The films are amorphous for deposition temperatures up to 1000 °C and crystalline, in the α-form, at 1200 °C and above. A method for evaluating the internal stresses based on the curvature of the silicon substrate wafer and the resulting silicon Raman peak shift was developed. Some amorphous films exhibit high internal tensile stresses that can lead to cracking during deposition depending on the mechanism and effective precursors involved. Residual stresses can thus be reduced and cracking avoided by, in descending order of importance, reducing the concentration of reactive gases through dilution, increasing the deposition temperature and decreasing the total pressure. The effects of these parameters on the intrinsic stresses were related to the amount of residual hydrogen successively incorporated and thermally released during the growth of the coating according to the Noskov's model.

Impact of Hydrogen‐Rich Silicon Nitride Material Properties on Light‐Induced Lifetime Degradation in Multicrystalline Silicon

The root cause of “Light and Elevated Temperature Induced Degradation” (LeTID) of the carrier lifetime in multicrystalline silicon (mc‐Si) wafers is investigated by depositing hydrogen‐rich silicon nitride (SiNx:H) films of different compositions on boron‐doped mc‐Si wafers. The extent of LeTID observed in mc‐Si after rapid thermal annealing (RTA) shows a positive correlation with the amount of hydrogen introduced from the SiNx:H layers into the bulk. The concentration of in‐diffused hydrogen is quantified via measuring the resistivity change due to the formation of boron–hydrogen pairs in boron‐doped float‐zone silicon wafers processed in parallel to the mc‐Si wafers. The measurements clearly show that the in‐diffusion of hydrogen into the silicon bulk during RTA depends on both the atomic density of the SiNx:H film as well as the film thickness. Importantly, the impact of SiNx:H film properties on LeTID shows the same qualitative dependence as the hydrogen content in the silicon bulk, providing evidence that hydrogen is involved in the LeTID defect activation process.

Development of MEMS MOS gas sensors with CMOS compatible PECVD inter-metal passivation

Metal oxide semiconductor (MOS) based micro-electromechanical sensors (MEMS) for gas measurement were developed using back-end-of-line (BEOL) compatible inter-metal dielectric films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD). As MOS MEMS require sintering above 600°C, a set of PECVD silicon oxide and nitride films was characterized before and after annealing up to 700°C, in order to identify the best candidate inter-metal dielectric materials. The effect of thermal load on the films was determined by measuring stress, thickness and refractive index after annealing both in dry air and nitrogen atmosphere. Nano-indentation was used to estimate the elastic modulus after annealing. The best performing films were employed as inter-metal dielectric in the full fabrication of microheater MEMS gas sensors. Among the selected films, only silicon oxide deposited with high frequency plasma generator allowed for the complete gas sensor fabrication with no damage. SnO2 paste was successfully screen printed on the fabricated membranes and sintered to enable gas sensing. Electrical and gas sensing tests were performed with the fabricated microheaters, demonstrating full functionality. Thermal stress endurance tests were also conducted, with no membrane deformation after more than 500,000 duty cycles. Results show that the proposed PECVD passivation is compliant up to 650°C firing temperature and 450°C operating temperature, and demonstrate the use of CMOS-BEOL PECVD inter-metal passivation for MOS MEMS gas sensor fabrication.

Parametric study and residual gas analysis of large-area silicon-nitride thin-film deposition by plasma-enhanced chemical vapor deposition

Large-area silicon-nitride thin films deposited from silane and ammonia by plasma-enhanced chemical vapor deposition are investigated experimentally in a 300 mm apparatus with a vertical showerhead. The responses of deposition rate and refractive index to the process parameters are found and discussed. The effects of showerhead configuration on the full-wafer deposition rate and refractive index are further examined, and the inherent non-uniformity is improved by using a proper convex showerhead. The residual gases are analyzed online, and a good correlation between the partial pressure of hydrogen and the deposition rate is found.