Search

Steady-state photocapacitance (SSPC) was conducted on nonpolar m-plane GaN n-type Schottky diodes to evaluate the defects induced by inductively coupled plasma (ICP) dry etching in etched-and-regrown unipolar structures. An ∼10× increase in the near-midgap Ec – 1.9 eV level compared to an as-grown material was observed. Defect levels associated with regrowth without an etch were also investigated. The defects in the regrown structure (without an etch) are highly spatially localized to the regrowth interface. Subsequently, by depth profiling an etched-and-regrown sample, we show that the intensities of the defect-related SSPC features associated with dry etching depend strongly on the depth away from the regrowth interface, which is also reported previously [Nedy et al., Semicond. Sci. Technol. 30, 085019 (2015); Fang et al., Jpn. J. Appl. Phys. 42, 4207–4212 (2003); and Cao et al., IEEE Trans. Electron Devices 47, 1320–1324 (2000)]. A photoelectrochemical etching (PEC) method and a wet AZ400K treatment are also introduced to reduce the etch-induced deep levels. A significant reduction in the density of deep levels is observed in the sample that was treated with PEC etching after dry etching and prior to regrowth. An ∼2× reduction in the density of Ec – 1.9 eV level compared to a reference etched-and-regrown structure was observed upon the application of PEC etching treatment prior to the regrowth. The PEC etching method is promising for reducing defects in selective-area doping for vertical power switching structures with complex geometries [Meyers et al., J. Electron. Mater. 49, 3481–3489 (2020)]. [ABSTRACT FROM AUTHOR]

We report a method for high‐fidelity lithographic patterning of the flexible β‐phase polyvinylidene difluoride (PVDF) film using traditional cleanroom equipment and commercially available materials. In our process, the chemically reactive gas of CHF3, CF4 and SF6 was used as a simple substance mixed with O2. The effects of process parameters on the PVDF dry etching characteristics were investigated by controlling that of Radio frequency (RF) power, process pressure, gas type and the mixed concentration in O2 as well as its mass flow rate. At a constant RF power (100 W) and associated process conditions, 40–70 µm of fine‐line patterns and several tens µm/h of high etch rate could be realized on a 110 µm‐thick β‐PVDF film without much loss of its piezoelectricity. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Reports that the Tohoku University researchers of Sendai, Japan, have applied pulse-time modulation technology to tailor plasma composition for specific processes. Generation of positive ions and radicals in the plasma; Application of the designed plasmas to solve specifuic manufacturing problems in etching; Control of the N density in plasma nitridization of ultrathin gate dielectric layers.

Discusses the outcome of the annual progress update meeting of Selete company in Tokyo, Japan in 2001. Plans of the Asuka Project researchers to select tools for the government's research fab in Tsukuba; Discussion on the plan of a Selete division for a node equipment and materials development; Update on the dry etching technology.