A Study on the Damage Layer Removal of Single-Crystal Silicon Wafer After Atmospheric-Pressure Plasma Etching

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Weijia Guo ◽  
Senthil Kumar Anantharajan ◽  
Xinquan Zhang ◽  
Hui Deng

Abstract In this study, atmospheric-pressure (AP) plasma generated using He/O2/CF4 mixture as feed gas was used to etch the single-crystal silicon (100) wafer and the characteristics of the etched surface were investigated. The wafer morphology and surface elemental composition were analyzed using scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The XPS results reveal that the fluorine element will be deposited on the wafer surface during the etching process when oxygen was not introduced as the feed gas. By detecting the energy and intensity of emitted particles, optical emission spectroscopy (OES) is used to identify the radicals in plasma. The fluorocarbon radicals generated during CF4 plasma ionization can form carbon fluoride polymer, which is considered as one factor to suppress the etching process. The roughness was measured to be changed with the increase in the etching time. The surface appears to be rougher at first when the plasma etching occurred on the subsurface damaged (SSD) layer, and the subsurface cracks would show on the surface after a short-time etching. After the damaged layer was fully removed, etching resulted in the formation of square-opening etching pits. During extended etching, the individual etching pits grew up and coalesced with one another; this coalescence provided an improved surface roughness. This study explains the AP plasma etching mechanism, and the formation of anisotropic surface etching pits at a microscale level for promoting the micromachining process.

2014 ◽  
Vol 778-780 ◽  
pp. 759-762 ◽  
Author(s):  
Yasuhisa Sano ◽  
Hiroaki Nishikawa ◽  
Yuu Okada ◽  
Kazuya Yamamura ◽  
Satoshi Matsuyama ◽  
...  

Silicon carbide (SiC) is a promising semiconductor material for high-temperature, high-frequency, high-power, and energy-saving applications. However, because of the hardness and chemical stability of SiC, few conventional machining methods can handle this material efficiently. A plasma chemical vaporization machining (PCVM) technique is an atmospheric-pressure plasma etching process. We previously proposed a novel style of PCVM dicing using slit apertures for plasma confinement, which in principle can achieve both a high removal rate and small kerf loss, and demonstration experiments were performed using a silicon wafer as a sample. In this research, some basic experiments were performed using 4H-SiC wafer as a sample, and a maximum removal rate of approximately 10 μm/min and a narrowest groove width of 25 μm were achieved. We also found that argon can be used for plasma generation instead of expensive helium gas.


1987 ◽  
Vol 65 (8) ◽  
pp. 892-896 ◽  
Author(s):  
R. E. Thomas ◽  
C. E. Norman ◽  
S. Varma ◽  
G. Schwartz ◽  
E. M. Absi

A low-cost, high-yield technology for producing single-crystal silicon solar cells at high volumes, and suitable for export to developing countries, is described. The process begins with 100 mm diameter as-sawn single-crystal p-type wafers with one primary flat. Processing steps include etching and surface texturization, gaseous-source diffusion, plasma etching, and contacting via screen printing. The necessary adaptations of such standard processes as diffusion and plasma etching to solar-cell production are detailed. New process developments include a high-throughput surface-texturization technique, and automatic printing and firing of cell contacts.The technology, coupled with automated equipment developed specifically for the purpose, results in solar cells with an average efficiency greater than 12%, a yield exceeding 95%, a tight statistical spread on parameters, and a wide tolerance to starting substrates (including the first 100 mm diameter wafers made in Canada). It is shown that with minor modifications, the present single shift 500 kWp (kilowatt peak) per year capacity technology can be readily expanded to 1 MWp per year, adapted to square and polycrystalline substrates, and efficiencies increased above 13%.


2013 ◽  
Vol 22 (3) ◽  
pp. 589-602 ◽  
Author(s):  
Michael S. Gaither ◽  
Richard S. Gates ◽  
Rebecca Kirkpatrick ◽  
Robert F. Cook ◽  
Frank W. DelRio

Doklady BGUIR ◽  
2019 ◽  
pp. 107-112
Author(s):  
Y. V. Zaporozhchenko ◽  
D. A. Kotov ◽  
A. V. Aksyuchits ◽  
A. N. Osipov ◽  
S. V. Paceev

The results of research the surface of single-crystal silicon, glass, and stainless steel after processing in a plasma at atmospheric pressure are presented. It has been experimentally proved that after processing, the adhesive properties of the surface of materials are significantly improved.


1983 ◽  
Vol 29 ◽  
Author(s):  
T. Arikado ◽  
M. Sekine ◽  
H. Okano ◽  
Y. Horiike

ABSTRACTSingle-crystal Si etching characteristics using an excimer laser (308 nm, XeCℓ) in the Cℓ2 gas have been studied. In lightly doped n-type and p-type Si, the etch rate of (100) is higher than that of (111), thus the (111) sidewall appears clearly for the irradiation to (100), while both orientations show almost the same etch rates in n+-doped Si. The n-type Si is etched spontaneously even by photo-dissociated Cℓ radicals generated in the gas phase, but no p-type Si etching occurs without direct irradiation. In addition, both types of etch rate-dependence on sheet resistance demonstrate that the number of electrons in the conduction band plays an essential role in the Si etching. This fact supports the field-assisted mechanism in the plasma etching proposed by Winters.


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