The Improvement of Wet Anisotropic Etching with Megasonic Wave

2005 ◽  
Vol 297-300 ◽  
pp. 557-561
Author(s):  
Woo Seong Che ◽  
Chang Gil Suk ◽  
Tae Gyu Park ◽  
Jun Tae Kim ◽  
Jun Hyub Park
Keyword(s):  
Surface Roughness ◽  
Etch Rate ◽  
Single Crystal Silicon ◽  
Wet Etching ◽  
Crystal Silicon ◽  
Original Surface ◽  
Magnetic Stirring ◽  
Wet Anisotropic Etching ◽  
P Type ◽  
Initial Root

A new method to improve the wet etching characteristics is described. The anisotropic wet-etching of (100) Si with megasonic wave has been studied in KOH solution. Etching characteristics of p-type (100) 6inch Si have been explored with and without megasonic irradiation. It has been observed that megasonic irradiation improves the characteristics of wet etching such as the etch rate, etch uniformity, surface roughness. The etching uniformity was less than ±1% on the whole wafer. The initial root-mean-squre roughness(Rrms) of single crystal silicon is 0.23nm [1]. It has been reported that the roughnesses with magnetic stirring and ultrasonic agitation were 566nm and 66nm [3]. But with megasonic irradiation, the Rrms of 1.7nm was achieved for the surface of 37µm depth. Wet etching of silicon with megasonic irradiation can maintain nearly the original surface roughness during etching. The results have verified that the megasonic irradiation is an effective way to improve the etching characteristics - the etch rate, etch uniformity and surface roughness.

Fabrication of Smooth GaN-Based Laser Facets

1998 ◽  
Vol 537 ◽  
Author(s):  
D. A. Stocker ◽  
E. F. Schubert ◽  
K. S. Boutros ◽  
J. M. Redwing
Keyword(s):  
Surface Roughness ◽  
Chemical Etching ◽  
Field Effect ◽  
Etch Rate ◽  
Wet Etching ◽  
High Resistivity ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
P Type ◽  
Scanning Electron

AbstractA method is presented for fabricating fully wet-etched InGaN/GaN laser cavities using photoenhanced electrochemical wet etching followed by crystallographic wet etching. Crystallographic wet chemical etching of n- and p-type GaN grown on c-plane sapphire is achieved using H3PO4 and various hydroxides, with etch rates as high as 3.2 μm/min. The crystallographic GaN etch planes are {0001}, {1010}, {1011}, {1012}, and {1013}. The vertical {1010} planes appear perfectly smooth when viewed with a field-effect scanning electron microscope (FESEM), indicating a surface roughness less than 5 nm, suitable for laser facets. The etch rate and crystallographic nature for the various etching solutions are independent of conductivity, as shown by seamless etching of a p-GaN/undoped, high-resistivity GaN homojunction.

Single-Crystal Silicon Etching Characteristics Using Excimer Laser Cℓ2 GAS

1983 ◽  
Vol 29 ◽  
Author(s):  
T. Arikado ◽  
M. Sekine ◽  
H. Okano ◽  
Y. Horiike
Keyword(s):  
Single Crystal ◽  
Gas Phase ◽  
Excimer Laser ◽  
Plasma Etching ◽  
Etch Rate ◽  
Single Crystal Silicon ◽  
Silicon Etching ◽  
Crystal Silicon ◽  
Direct Irradiation ◽  
P Type

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.

25 nm Single-Crystal Silicon Nanowires Fabricated by Anisotropic Wet Etching

2017 ◽  
Vol 17 (2) ◽  
pp. 1525-1529
Author(s):  
Hoang Manh Chu ◽  
Minh Van Nguyen ◽  
Hung Ngoc Vu ◽  
Kazuhiro Hane
Keyword(s):  
Single Crystal ◽  
Silicon Nanowires ◽  
Single Crystal Silicon ◽  
Wet Etching ◽  
Crystal Silicon

scholarly journals Experimental Research on Discharge Forming Cutting-Electrochemical Machining of Single-Crystal Silicon

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bin Xin ◽  
Wei Liu
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Electrochemical Machining ◽  
Single Crystal Silicon ◽  
Recast Layer ◽  
Movement Speed ◽  
Crystal Silicon ◽  
Wedm Process

During the wire electrical discharge machining (WEDM) process, a large number of discharge pits and a recast layer are easily generated on the workpiece surface, resulting in high surface roughness. A discharge forming cutting-electrochemical machining method for fabricating single-crystal silicon is proposed in this study to solve this problem. On the same processing equipment, single-crystal silicon is first cut using the discharge forming cutting method. Second, electrochemical anodic reaction technology is used to dissolve the discharge pits and recast layer on the single-crystal silicon surface. The machining mechanism of this process, the surface elements of the processed single-crystal silicon and a comparison of the kerf width are analyzed through experiments. On this basis, the influence of the movement speed of the copper foil electrode during electrochemical anodic dissolution on the final surface roughness is qualitatively analyzed. The experimental results show that discharge forming cutting-electrochemical machining can effectively eliminate the electrical discharge pits and recast layer, which are caused by electric discharge cutting, on the surface of single-crystal silicon, thereby reducing the surface roughness of the workpiece.

Microheater Made of Heavily Boron Doped Single Crystal Silicon Beam

1992 ◽  
Vol 276 ◽  
Author(s):  
Mitsuteru Kimura ◽  
Kazuhiro Komatsuzaki
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Bridge Structure ◽  
Quick Response ◽  
Crystal Silicon ◽  
Etching Technique ◽  
Small Power ◽  
Boron Doped ◽  
Type Layer ◽  
P Type

ABSTRACTMicroheater made of heavily Boron doped single crystal Si beam covered with SiO2 film, 1000×300×3 μm, is fabricated on the n type Si substrate by the anisotropic etching technique. As this microheater has an air bridge structure of low resistivity semiconductor material with positive but small temperature coefficient of resistance, a broad heating area up to 800 °C is easily obtained and it has quick response with the thermal time constant t of about 4 ms and has small power consumption. Since this heating area is made of p type layer in the n type substrate,this area can be electrically isolated from the substrate because of the formation of p-n junction.

Semi-automatic, volume production of silicon solar cells

1987 ◽  
Vol 65 (8) ◽  
pp. 892-896 ◽  
Author(s):  
R. E. Thomas ◽  
C. E. Norman ◽  
S. Varma ◽  
G. Schwartz ◽  
E. M. Absi
Keyword(s):  
Solar Cells ◽  
Single Crystal ◽  
Plasma Etching ◽  
Low Cost ◽  
Single Crystal Silicon ◽  
High Yield ◽  
Silicon Solar Cells ◽  
Crystal Silicon ◽  
Volume Production ◽  
P Type

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%.

Supersaturated P-Type Polycrystaline Films Produced by Rapid Thermal Annealing of High Dose Boron Ion Implants for Interconnects and Shallow Junction Diffusion Sources

1990 ◽  
Vol 182 ◽  
Author(s):  
B. Raicu ◽  
M.I. Current ◽  
W.A. Keenan ◽  
D. Mordo ◽  
R. Brennan ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Thermal Annealing ◽  
Cross Section ◽  
Rapid Thermal Annealing ◽  
Single Crystal Silicon ◽  
High Dose ◽  
Crystal Silicon ◽  
Polysilicon Films ◽  
P Type

AbstractHighly conductive p+-polysilicon films were fabricated over Si(100) and SiO2 surfaces using high-dose ion implantation and rapid thermal annealing. Resistivities close to that of single crystal silicon were achieved. These films were characterized by a variety of electrical and optical techniques as well as SIMS and cross-section TEM.

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