scholarly journals Research on Sapphire Deep Cavity Corrosion and Mask Selection Technology

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 136
Author(s):  
Yiingqi Shang ◽  
Hongquan Zhang ◽  
Yan Zhang
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Chemical Vapor ◽  
Nitride Layer ◽  
Wet Etching ◽  
Silicon Dioxide Layer ◽  
Etching Depth ◽  
Deep Cavity ◽  
Mask Layer ◽  
Layer Composite

Aimed at the problem of the small wet etching depth in sapphire microstructure processing technology, a multilayer composite mask layer is proposed. The thickness of the mask layer is studied, combined with the corrosion rate of different materials on sapphire in the sapphire etching solution, different mask layers are selected for the corrosion test on the sapphire sheet, and then the corrosion experiment is carried out. The results show that at 250 °C, the choice is relatively high when PECVD (Plasma Enhanced Chemical Vapor Deposition) is used to make a double-layer composite film of silicon dioxide and silicon nitride. When the temperature rises to 300 °C, the selection ratio of the silicon dioxide layer grown by PECVD is much greater than that of the silicon nitride layer. Therefore, under high temperature conditions, a certain thickness of silicon dioxide can be used as a mask layer for deep cavity corrosion.

Development of Low Temperature Silicon Nitride and Silicon Dioxide Films by Inductively-Coupled Plasma Chemical Vapor Deposition

1999 ◽  
Vol 573 ◽  
Author(s):  
J. W. Lee ◽  
K. D. Mackenzie ◽  
D. Johnson ◽  
S. J. Pearton ◽  
F. Ren ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Silicon Nitride ◽  
Low Temperature ◽  
Silicon Dioxide ◽  
Vapor Deposition ◽  
Inductively Coupled Plasma ◽  
Chemical Vapor ◽  
Plasma Chemical Vapor Deposition ◽  
Inductively Coupled ◽  
Silicon Dioxide Films

ABSTRACTHigh-density plasma technology is becoming increasingly attractive for the deposition of dielectric films such as silicon nitride and silicon dioxide. In particular, inductively-coupled plasma chemical vapor deposition (ICPCVD) offers a great advantage for low temperature processing over plasma-enhanced chemical vapor deposition (PECVD) for a range of devices including compound semiconductors. In this paper, the development of low temperature (< 200°C) silicon nitride and silicon dioxide films utilizing ICP technology will be discussed. The material properties of these films have been investigated as a function of ICP source power, rf chuck power, chamber pressure, gas chemistry, and temperature. The ICPCVD films will be compared to PECVD films in terms of wet etch rate, stress, and other film characteristics. Two different gas chemistries, SiH4/N2/Ar and SiH4/NH3/He, were explored for the deposition of ICPCVD silicon nitride. The ICPCVD silicon dioxide films were prepared from SiH4/O2/Ar. The wet etch rates of both silicon nitride and silicon dioxide films are significantly lower than films prepared by conventional PECVD. This implies that ICPCVD films prepared at these low temperatures are of higher quality. The advanced ICPCVD technology can also be used for efficient void-free filling of high aspect ratio (3:1) sub-micron trenches.

Selective Nitride Etch by Using Fluorides in High Boiling Point Solvent

2012 ◽  
Vol 195 ◽  
pp. 50-54
Author(s):  
Hsing Chen Wu ◽  
Emanuel I. Cooper ◽  
Heng Kai Hsu
Keyword(s):  
Silicon Nitride ◽  
Phosphoric Acid ◽  
Boiling Point ◽  
Silicon Oxide ◽  
Nitride Layer ◽  
Wet Etching ◽  
High Boiling Point ◽  
Le Châtelier Principle ◽  
Le Chatelier Principle

Conventional wet etching techniques for selectively removing silicon nitride (Si3N4) have utilized hot (approximately 145-180°C) aqueous phosphoric acid (H3PO4) solutions (often referred to as hot phos). The typical Si3N4:SiO2 selectivity is about 40:1 when using 85% fresh hot phosphoric acid. Advantageously, as the nitride layer is removed, hydrated silicon oxide forms and dissolves in the etchant. Consistent with Le Chatelier principle, this inhibits the additional removal of silicon oxide from the device surface; thus selectivity gradually increases with use [.

Plasma Etching of Silicon Dioxide and Silicon Nitride with Non-Perfluorocompound Chemistries: Trifluoroacetic Anhydride and Iodofluorocarbons

1996 ◽  
Vol 447 ◽  
Author(s):  
Simon M. Karecki ◽  
Laura C. Pruette ◽  
L. Rafael Reif
Keyword(s):  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Plasma Etching ◽  
Etch Rate ◽  
Gas Flow ◽  
Sulfur Hexafluoride ◽  
Semiconductor Industry ◽  
Chemical Vapor ◽  
Trifluoroacetic Anhydride ◽  
Auger Electron Spectroscopy Data

AbstractPresently, the semiconductor industry relies almost exclusively on perfluorocompounds (e.g., tetrafluoromethane, hexafluoroethane, nitrogen trifluoride. sulfur hexafluoride, and. more recently, octafluoropropane) for the etching of silicon dioxide and silicon nitride films in wafer patterning and PECVD (plasma enhanced chemical vapor deposition) chamber cleaning applications. The use of perfluorocompounds (PFCs) by the industry is considered problematic because of the high global warming potentials (GWPs) associated with these substances. Potential replacements for perfluorocompounds are presently being evaluated at MIT. In an initial stage of the study, intended to screen potential candidates on the basis of etch performance, a large number of compounds is being tested in a commercially available magnetically enhanced reactive ion etch tool. The potential alternatives discussed in this work are trifluoroacetic anhydride (TFAA) and three members of the iodofluorocarbon (IFC) family – iodotrifluoromethane, iodopentafluorocthane, and 2-iodoheptafluoropropane. This paper will present the results of etch rate comparisons between TFAA and octafluoropropane, a perfluorinated dielectric etchant. Designed experiment (DOE) methodology, combined with neural network software, was used to study a broad parameter space of reactor conditions. The effects of pressure, magnetic field, and gas flow rates were studied. Additionally, more limited tests were carried out with the three iodofluorocarbon gases. Etch rate data, as well as Auger electron spectroscopy data from substrates exposed to IFC plasmas will be presented. All gases were evaluated using both silicon dioxide as well as silicon nitride substrates. Results indicate that these compounds may be potentially viable in plasma etching applications.

scholarly journals Functional nano-structuring of thin silicon nitride membranes

2020 ◽  
Vol 71 (2) ◽  
pp. 127-130
Author(s):  
Milan Matějka ◽  
Stanislav Krátký ◽  
Tomáš Řiháček ◽  
Alexandr Knápek ◽  
Vladimír Kolařík
Keyword(s):  
Silicon Nitride ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Single Crystal Silicon ◽  
Nitride Layer ◽  
Functional Layer ◽  
Crystal Silicon ◽  
Mask Layer ◽  
Application Potential ◽  
Silicon Frame

AbstractThe paper describes the development and production of a nano-optical device consisting of a nano-perforated layer of silicon nitride stretched in a single-crystal silicon frame using electron beam lithography (EBL) and reactive ion etching (RIE) techniques. Procedures for transferring nanostructures to the nitride layer are described, starting with the preparation of a metallic mask layer by physical vapor deposition (PVD), high-resolution pattern recording technique using EBL and the transfer of the motif into the functional layer using the RIE technique. Theoretical aspects are summarized including technological issues, achieved results and application potential of patterned silicon nitride membranes.

High-Frequency SiC MESFETs with Silicon Dioxide/Silicon Nitride Passivation

2006 ◽  
Vol 527-529 ◽  
pp. 1239-1242
Author(s):  
Kevin Matocha ◽  
Ed Kaminsky ◽  
Alexey Vertiatchikh ◽  
Jeff B. Casady
Keyword(s):  
Silicon Nitride ◽  
Surface Passivation ◽  
Chemical Vapor ◽  
Drain Current ◽  
Nitride Layer ◽  
Class Ab ◽  
Power Added Efficiency ◽  
Thermal Oxide ◽  
Pressure Chemical ◽  
Recessed Channel

4H-SiC MESFETs were fabricated using a bilayer dry thermal oxide/low-pressure chemical vapor deposited (LPCVD) silicon nitride for surface passivation. The passivation dielectric consists of a 20 nm thick dry thermal oxide covered by a 45 nm thick LPCVD silicon nitride layer. Devices utilize a recessed-channel architecture with 0.6 micron T-gates. Devices with the bilayer SiO2/SiNx passivation achieved a ft=9.3 GHz and fmax=15.5 GHz (WG=1.5 mm). The device transconductance was 34 mS/mm, drain current density was 235 mA/mm, and pinchoff voltage was –8V. Devices were load-pull characterized at 3 GHz with a 10% duty cycle and 100 μs repetition rate and a Class AB quiescent bias of IDS=100 mA/mm, and VDS=30V. Large devices with a 9.6 mm gate-periphery deliver an output power of 43.2 dBm (20.9 W=2.2W/mm) with a power-added-efficiency of 59% at a gain of 8.8 dB.

Performance of Polycrystalline Silicon Thin Film Transistors with Double Layer Gate Dielectric

1992 ◽  
Vol 284 ◽  
Author(s):  
Ji-Ho Kung ◽  
Miltiadis K. Hatalis ◽  
Jerzy Kanicki
Keyword(s):  
Thin Film ◽  
Silicon Nitride ◽  
Silicon Dioxide ◽  
Double Layer ◽  
Thin Film Transistors ◽  
Gate Dielectric ◽  
Nitride Layer ◽  
Silicon Thin Film ◽  
Bias Stress ◽  
Effective Carrier

ABSTRACTThe electrical characteristics of n- and p-channel poly-Si thin film transistors having a double layer gate dielectric structure are reported. The gate dielectric consists of a silicon dioxide layer and a nitrogen-rich silicon nitride layer, both deposited by PECVD at low temperatures (≥400° C). When the silicon nitride was in contact with the poly-Si film, the effective carrier mobility (μeff), threshold voltage (Vth and subthreshold swing (St) for n-channel devices were 36 cm2/Vsec, -1.8 V and 1.65 V/decade, respectively, while for p-channel devices were 6 cm2/Vsec, -37 and 2.47 V/decade, respectively. These devices were not stable under negative gate bias stress, due to the injection of holes into the silicon nitride. When silicon dioxide was in contact with the poly-Si film, the μeff, Vth and St for n-channel devices were 26 cm2/Vsec, 3 V and 1.63 V/decade, respectively, while for p-channel devices were 10 cm2/Vsec, -22 V and 1.52 V/decade, respectively. These devices were stable under d.c. bias stress.

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