Feature evolution during plasma etching. II. Polycrystalline silicon etching

2000 ◽  
Vol 18 (1) ◽  
pp. 188-196 ◽  
Author(s):  
J. M. Lane ◽  
F. P. Klemens ◽  
K. H. A. Bogart ◽  
M. V. Malyshev ◽  
J. T. C. Lee
Keyword(s):  
Plasma Etching ◽  
Polycrystalline Silicon ◽  
Silicon Etching ◽  
Feature Evolution

Submicronic etched features of silicon with high aspect ratio obtained by cryogenic plasma deep-etching through perforated polymer thin films

2015 ◽  
Vol 1803 ◽  
Author(s):  
A. Vital ◽  
M. Boufnichel ◽  
R. Dussart ◽  
N. Gosset ◽  
P. Lefaucheux ◽  
...  
Keyword(s):  
Thin Films ◽  
Aspect Ratio ◽  
Plasma Etching ◽  
Silicon Substrate ◽  
Etching Rate ◽  
Minor Component ◽  
Selective Extraction ◽  
Silicon Substrates ◽  
Silicon Etching ◽  
Immiscible Polymer Blends

ABSTRACTWe report the preparation of nanomasks for silicon plasma etching, which is not based on full top-down approaches such as conventional lithographic process. We used laterally phase separated polymers thin films (30 to 100 nm thick) obtained from immiscible polymer blends of poly(styrene) PS and poly(lactide) PLA, PS being the major component, spin-coated onto silicon substrates. Despite the high incompatibility of the two polymers, submicronic domains were obtained in the film. The selective extraction of the minor component (PLA) led to the formation of a perforated layer of PS at the top of the silicon substrate, and was used as a mask for the selective etching of the silicon. For that purpose, we used a cryogenic etching process where the silicon substrate was cooled at a cryogenic temperature (∼ -120°C) and exposed to a monocyclic SF6/O2 plasma. It was possible to etch anisotropic profiles with vertical sidewalls and minimal defects. Etched feature with an aspect ratio of 7 were obtained in these conditions. We determined that the selectivity of etching (Si/PS) was 11:1, with a silicon etching rate of 0.8 µm/min. The selectivity of these masks was further increased when using the inorganic replicas of the polymer template (50:1) or with chemical modifications of the PS by RuO4 (80:1), allowing for increased aspect ratio etched features (up to 20 in the latter case). Optimized etching processes (such as STiGer process) were also used in order to improve the reproducibility and robustness of the method.

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.

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