Temperature-dependent radiative and non-radiative dynamics of photo-excited carriers in extremely high-density and small InGaN nanodisks fabricated by neutral-beam etching using bio-nano-templates

Abstract Even though EUV lithography has the advantage of implenting a finer pattern compared to ArF immersion lithography due to the use of 13.5 nm instead of 193 nm as the wavelengh of the light source, due to the low energy of EUV light source, EUV resist has a thinner thickness than conventional ArF resist. EUV resist having such a thin thickness is more vulnerable to radiation damage received during the etching because of its low etch resistance and also tends to have a problem of low etch selectivity. In this study, the radiation damage to EUV resist during etching of hardmask materials such as Si3N4, SiO2, etc. using CF4 gas was compared between neutral beam etching (NBE) and ion beam etching (IBE). When NBE was used, after the etching of 20 nm thick EUV resist, the line edge roughness (LER) increase and the critical dimension (CD) change of EUV resist were reduced by ~ 1/3 and ~ 1/2, respectively, compared to those by IBE. Also, at that EUV etch depth, the RMS(root mean square) surface roughness value of EUV resist etched by NBE was ~2/3 compared to that by IBE on the average. It was also confirmed that the etching selectivity between SiO2, Si3N4, etc. and EUV resist was higher for NBE compared to IBE. The less damage to the EUV resist and the higher etch selectivity of materials such as Si3N4 and SiO2 over EUV resist for NBE compared to IBE are believed to be related to the no potential energy released by the neutralization of the ions during the etching for NBE.

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Fabrication of three-dimensional Si quantum dot array by fusion of biotemplate and neutral beam etching

Silicon Nanomaterials Sourcebook ◽

10.4324/9781315153551-5 ◽

2017 ◽

pp. 87-106

Author(s):

Seiji Samukawa

Keyword(s):

Quantum Dot ◽

Three Dimensional ◽

Neutral Beam ◽

Si Quantum Dot ◽

Neutral Beam Etching

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Effects of Frequency and Temperature on Electric Field Mitigation Method via Protruding Substrate Combined with Applying Nonlinear FDC Layer in Wide Bandgap Power Modules

Energies ◽

10.3390/en13082022 ◽

2020 ◽

Vol 13 (8) ◽

pp. 2022 ◽

Cited By ~ 3

Author(s):

Maryam Mesgarpour Tousi ◽

Mona Ghassemi

Keyword(s):

Electrical Conductivity ◽

Electric Field ◽

Metal Layer ◽

Wide Bandgap ◽

High Density ◽

Field Calculation ◽

Power Module ◽

Temperature Dependent ◽

Ac Electrical Conductivity ◽

Power Modules

Our previous studies showed that geometrical techniques including (1) metal layer offset, (2) stacked substrate design and (3) protruding substrate, either individually or combined, cannot solve high electric field issues in high voltage high-density wide bandgap (WBG) power modules. Then, for the first time, we showed that a combination of the aforementioned geometrical methods and the application of a nonlinear field-dependent conductivity (FDC) layer could address the issue. Simulations were done under a 50 Hz sinusoidal AC voltage per IEC 61287-1. However, in practice, the insulation materials of the envisaged WBG power modules will be under square wave voltage pulses with a frequency of up to a few tens of kHz and temperatures up to a few hundred degrees. The relative permittivity and electrical conductivity of aluminum nitride (AlN) ceramic, silicone gel, and nonlinear FDC materials that were assumed to be constant in our previous studies, may be frequency- and temperature-dependent, and their dependency should be considered in the model. This is the case for other papers dealing with electric field calculation within power electronics modules, where the permittivity and AC electrical conductivity of the encapsulant and ceramic substrate materials are assumed at room temperature and for a 50 or 60 Hz AC sinusoidal voltage. Thus, the big question that remains unanswered is whether or not electric field simulations are valid for high temperature and high-frequency conditions. In this paper, this technical gap is addressed where a frequency- and temperature-dependent finite element method (FEM) model of the insulation system envisaged for a 6.5 kV high-density WBG power module will be developed in COMSOL Multiphysics, where a protruding substrate combined with the application of a nonlinear FDC layer is considered to address the high field issue. By using this model, the influence of frequency and temperature on the effectiveness of the proposed electric field reduction method is studied.

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