DUV Wavelength Research Articles

Anisotropic conductive film (ACF) step-by-step line ablation using NIR, green, and DUV wavelengths femtosecond laser for Micro-LED display repair

Anisotropic conductive film (ACF) step-by-step line ablation using NIR, green, and DUV wavelengths femtosecond laser for Micro-LED display repair

Ablation morphology and characteristic analysis of anisotropic conductive film (ACF) using femtosecond lasers with NIR, Green, and DUV wavelengths for micro-LED display repair

Ablation morphology and characteristic analysis of anisotropic conductive film (ACF) using femtosecond lasers with NIR, Green, and DUV wavelengths for micro-LED display repair

Influence of Thin Fluorine Resin Film on DUV LED Packaging Devices

Amorphous fluorine resin is a promising material that can be used for the encapsulation of deep-ultraviolet light-emitting diodes (DUV LEDs) to promote the light output, due to its light characteristics which mean it shows no absorption in the DUV wavelength region. However, obvious decay and high cost are the problems faced by fluorine resin. In this study, thin-fluorine-resin-film-packaged DUV LEDs were fabricated by the drip-coating method and the characteristics were tested. The results show that the light output power increased from 4.95 mW to 5.44 mW at 40 mA, and the cost of fluorine resin can be reduced to ~10%. In addition, no degradation during the aging was observed. However, when the light output power reached 12 mW or higher, >10% decay was observed after aging for 1000 h. In conclusion, thin-fluorine-resin-film-packaged DUV LEDs can achieve 10% light output power enhancement by using less fluorine resin material, and the material is more applicable to low-power DUV LEDs.

Maximizing the Light Extraction Efficiency for AlGaN-Based DUV-LEDs with Two Optimally Designed Surface Structures under the Guidance of PSO

A novel method of utilizing an intelligent algorithm to guide the light extraction surface structure designing process for deep-ultraviolet light emitting diodes (DUV-LEDs) is proposed and investigated. Two kinds of surface structures based on the truncated pyramid array (TPA) and truncated cone array (TCA) are applied, which are expected to suppress the total internal reflection (TIR) effect and increase the light extraction efficiency (LEE). By addressing particle swarm optimization (PSO), the TPA and TCA microstructures constructed on the sapphire layer of the flip-chip DUV-LEDs are optimized. Compared to the conventional structure design method of parameter sweeping, this algorithm has much higher design efficiency and better optical properties. At the DUV wavelength of 280 nm, as a result, significant increases of 221% and 257% on the LEE are realized over the two forms of optimized surface structures. This approach provides another design path for DUV-LED light extraction structures.

Growth of high-quality transparent SrB4O7 single crystals with high degradation resistance for DUV laser application

We grew borate crystals, SrB4O7 (SBO), by the top-seeded solution growth (TSSG) method. High-quality transparent SBO single crystals were successfully obtained from the stoichiometric melt by a seed cooling technique. The optical properties of the SBO crystals, which showed wide transparency, high transmittance, and high resistance to optical damage compared with synthetic silica glass and CsLiB6O10 (CLBO) crystals, were evaluated. Our results reveal for the first time that the SBO crystals exhibit outstanding degradation resistance at a DUV wavelength of 266 nm.

Functional Properties of Novel Metallic Hard Masks

Hard masks play an important role in pattern transfer to the desired substrate in the semiconductor lithography processes. Organic and inorganic type hard masks are used. While most organic hard masks such as carbon and siloxane type are solution spin coated, inorganic type hard masks such as SiON and SiN are either chemical vapor deposited (CVD) or atomic layer deposited (ALD). Future generation of lithography processes require hard masks with higher resistance to fluorinated plasma and materials that can be easily wet stripped after pattern transfer process to prevent dry etch damage to the substrate underneath.The present paper describes formation and functional properties of novel metal oxide hard masks by simple solution spin coating process. These novel metal oxide hard masks offer good etch selectivity and can easily be partially or fully wet strippable using commonly used chemicals in the FABs. The spin coatable composition has good long-term shelf life and pot life stability based on solution LPC analysis and wafer defect studies. The hard mask material absorbs DUV wavelengths and can be used as a spin-on inorganic or hybrid antireflective coating to control substrate reflectivity under DUV exposure of photoresist. At the same time they are transparent at 500-700nm for alignment mark identification and can be spin coatable up to 450nm thickness with good film quality. Some of these metal-containing materials can be used as an underlayer in EUV lithography to significantly enhance sensitivity of the photoresist. Specific metal hard masks are also developed for via or trench filling applications in IRT processes. The materials have shown good coating and lithography performance with a film thicknesses as low as 10 nm under ArF dry or immersion conditions.

Tuning Metamaterials for Applications at DUV Wavelengths

The unique properties of metamaterials, namely, their negative refractive index, permittivity, or permeability, have gained much recent attention. Research into these materials has led to the realization of a host of applications that may be useful to enhance optical nanolithography. A selection of materials has been examined both experimentally and theoretically to verify their support of surface plasmons, or lack thereof, in the DUV spectrum via the attenuated total reflection (ATR) method using the Kretschmann configuration. At DUV wavelengths, materials that were previously useful at mid-UV and longer wavelengths no longer act as metamaterials. Structured materials comprised of alternating layers of aluminum and aluminum oxide (Al2O3), as well as some other absorption-free dielectrics, exhibit metamaterial behavior, as do some elemental materials such as aluminum. These elemental and structured materials exhibit the best properties for use in plasmonic nanolithographic applications. Therefore, a simulator was created to examine material and thickness combinations to generate a tunable metamaterial for use in the DUV. A method for performing plasmonic interference lithography with this metamaterial has been proposed, with calculations showing the potential for half-pitch imaging resolution of 25 nm.

Fib repair of reticle defects with antistaining - effects on optical lithography from g-line to duv

Abstract Focused ion beam repair of opaque defects in photomasks and reticles has significant advantages over laser repair methods. The technique can however leave residual defects due to metal ion stains and other damage. A single step plasma etch antistain process has therefore been developed. However, by using an optimised approach to the FIB etch stage, post repair stain effects can be eliminated without the need for post repair antistaining. The effectiveness of the FIB repair method is demonstrated through wafer exposure trials using repaired reticles at G-line, I-line and DUV wavelengths.

The manufacture of rim phase shiftin reticles

Abstract RIM Phase Shifting is one of a number of Phase Shifting Techniques being considered to bring potential advantages of improved resolution and better process latitude to optical projection printing in the volume production of high density MB DRAMS with minimum feature sizes down to 0.3μm(1,2,3). This paper describes a production process developed under the ISL project capable of manufacturing rim shifted PSMs for use at g line, i line and DUV wavelengths. The formidable issues of inspection and repair for all types of PSMs are not discussed. The ISL technique uses quartz substrate Reactive Ion Etching, (R.I.E) for the phase shift, and wet chrome etching for the production of the rim. Optical and E-beam resists were used for reticle manufacture.