Porous silicon formation and etching process for use in silicon micromachining
A reproducible process for uniformly etching silicon from a series of micromechanical structures used in electrical devices and the like includes providing a micromechanical structure having a silicon layer with defined areas for removal thereon and an electrochemical cell containing an aqueous hydrofluoric acid electrolyte. The micromechanical structure is submerged in the electrochemical cell and the defined areas of the silicon layer theron are anodically biased by passing a current through the electrochemical cell for a time period sufficient to cause the defined areas of the silicon layer to become porous. The formation of the depth of the porous silicon is regulated by controlling the amount of current passing through the electrochemical cell. The micromechanical structure is then removed from the electrochemical cell and submerged in a hydroxide solution to remove the porous silicon. The process is subsequently repeated for each of the series of micromechanical structures to achieve a reproducibility better than 0.3%. 1 fig.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (USA)
- DOE Contract Number:
- AC04-76DP00789
- Assignee:
- Dept. of Energy
- Patent Number(s):
- PATENTS-US-A7478376
- Application Number:
- ON: DE91011575; PPN: US 7-478376
- OSTI ID:
- 5937851
- Country of Publication:
- United States
- Language:
- English
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Porous siliconformation and etching process for use in silicon micromachining
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Related Subjects
36 MATERIALS SCIENCE
SILICON
ETCHING
COATINGS
ELECTROCHEMICAL CELLS
HYDROFLUORIC ACID
INVENTIONS
MICROELECTRONIC CIRCUITS
POROUS MATERIALS
SEMICONDUCTOR DEVICES
ELECTRONIC CIRCUITS
ELEMENTS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
MATERIALS
SEMIMETALS
SURFACE FINISHING
426000* - Engineering- Components
Electron Devices & Circuits- (1990-)
360601 - Other Materials- Preparation & Manufacture