Rie-Induced Damage to Single Crystal Silicon Monitored with Nondestructive Thermal Waves

1986 ◽  
Vol 68 ◽  
Author(s):  
Patrice Geraghty ◽  
W. Lee Smith

AbstractA method is presented to nondestructively monitor damage in silicon caused by reactive-ion or plasma etching on actual product wafers or test wafers immediately following the etch step.Data is taken on product wafers by scanning the 1-micron laser probe spot across and along the bottom of RIE-etched trenches.The onset of silicon damage brings a marked increase to the thermal wave (TW) signal: as the RIE bias voltage was increased from -60 volts to -250 volts, the TW signal increased monotonically by 1230%.The effects of other RIE process parameters on the damage level were also measured.This study allowed the RIE process variables to be adjusted to minimize damage to the silicon surface.

2006 ◽  
Vol 48 (10) ◽  
pp. 2016-2020 ◽  
Author(s):  
M. V. Gomoyunova ◽  
D. E. Malygin ◽  
I. I. Pronin

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.


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%.


1993 ◽  
Vol 8 (6) ◽  
pp. 1334-1340 ◽  
Author(s):  
B.R. Stoner ◽  
S.R. Sahaida ◽  
J.P. Bade ◽  
P. Southworth ◽  
P.J. Ellis

Highly oriented diamond films were grown on single-crystal silicon substrates. Textured films were first nucleated by a two-step process that involved the conversion of the silicon surface to an epitaxial SiC layer, followed by bias-enhanced nucleation. The nucleation stage, which produced a partially oriented diamond film, was immediately followed by a (100) textured growth process, thus resulting in a film surface where approximately 100% of the grains are epitaxially oriented relative to the silicon substrate. The diamond films were characterized by both SEM and Raman spectroscopy. Structural defects in the film are discussed in the context of their potential effect on the electrical characteristics of the resulting film.


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