Hydrogen etching of the SiC(0001) surface at moderate temperature

Author(s):  
Toshiya Hamasaki ◽  
Kazuma Yagyu ◽  
Hisashi Mitani ◽  
Takashi Nishida ◽  
Hiroshi Tochihara ◽  
...  
Author(s):  
Zeyu Zhao ◽  
Jun Gao ◽  
Yuqing Meng ◽  
Kyle S. Brinkman ◽  
Jianhua Tong
Keyword(s):  

2018 ◽  
Vol 452 ◽  
pp. 314-321 ◽  
Author(s):  
Yuanpeng Chen ◽  
Hongwei Liang ◽  
Qasim Abbas ◽  
Jun Liu ◽  
Jianjun Shi ◽  
...  

2003 ◽  
Vol 10 (01) ◽  
pp. 55-63 ◽  
Author(s):  
M. DIANI ◽  
J. DIOURI ◽  
L. KUBLER ◽  
L. SIMON ◽  
D. AUBEL ◽  
...  

In 6H- or 4H-SiC(0001) surface technology, a Si-rich 3 × 3 reconstruction is usually first prepared by heating at 800°C under Si flux, and two other most stable [Formula: see text] or [Formula: see text] reconstructions are obtained by further extensive annealing at higher temperatures ranging between 900 and 1250°C. The 3 × 3 Si excess is thus progressively depleted up to a graphitized C-rich surface. By crystallographic (LEED) and chemical surface characterizations (XPS and UPS), we show that all these reconstructions can be obtained at a unique, low formation temperature of 800°C if the Si richness is controlled before annealing. This control is achieved by exposing the 3 × 3 surface to atomic hydrogen at room temperature. This procedure allows one to etch or partially deplete the (3 × 3)-associated Si excess, and make it more comparable to the final Si coverages, required to form the less Si-rich [Formula: see text] or [Formula: see text] reconstructions. After annealing at 800°C, the latter reconstructions are no longer determined by the heating time or temperature but only by the initial Si coverage set by the H doses inducing the low temperature etching. The high temperature treatment, required to remove by sublimation a significant Si amount associated with the Si-rich 3 × 3 reconstruction, is thus avoided. Such a methodology could be applied to other binary systems in the formation of reconstructions that depends on surface richness.


It is well known that when thin leaves of gold or silver are mounted upon glass and heated to a temperature which is well below a red heat, a remarkable change of properties takes place, whereby the continuity of the metallic film is destroyed. The result is that white light is now freely transmitted, reflection is correspondingly diminished, while the electric resistivity is enormously increased. A simple method of illustrating this extraordinary change is to mount a sheet of silver leaf between two clean lantern plates, clip them lightly together by means of wire paper fasteners or other suitable means, and then heat gradually to a temperature of not more than 500°C. This can be done con­veniently by placing the plates on a thin fire-brick in a cold gas muffle, and then raising the temperature to the desired point. The gas should now be turned off, and the glass plates allowed to cool slowly, so as to avoid cracking. They can then be bound with strips like an ordinary lantern plate, and a permanent example of transparent silver is obtained. It will be found that such a plate transmits the light of the electric lantern almost as readily as ordinary glass, and does not produce any change of colour. The great trans­parency of the film may be shown by placing the plate upon printing or writing, and photographing the characters through the plate. Every detail of the characters can be reproduced with remarkable clearness. At first sight it is perhaps difficult to conceive that so distinct an impression could be obtained through what was originally a perfectly opaque sheet of silver, and which has only been once heated to a moderate temperature.


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