Reactive sputter etching of silicon with very low mask-material etch rates
Directional etching of deep structures in silicon is often made difficult by a high mask erosion rate. Recent results have given a Si/SiO/sub 2/ etch rate ratio of up to 8 without the undercut problems associated with other selective etches. In this paper a new selectivity mechanism is described which can reproducibly give Si/SiO/sub 2/ etch rate ratios of more than 100 with a nonloading target, and more than about 50 with a loading target. Similar etch ratios are also obtained with masks of MgF/sub 2/, Al/sub 2/O/sub 3/, Al, and Cr. The inherently high Si/SiO/sub 2/ etch rate ratio obtained in Ar/Cl/sub 2/ discharges is here enhanced by causing selective deposition of SiO/sub 2/ onto slowly etched materials. The silicon may be obtained from the target, or, for easier control, from input gases such as SiCl/sub 4/. The deposition rate is controlled by the oxygen concentration. The results of etching deep grooves in Si are presented. Etch-mask faceting and Si surface decoration appear to limit the attainable etch rate ratios with fine structures; however, 18-..mu..m-deep gratings of 4.5-..mu..m period have been etched in Si.
- Research Organization:
- Massachusetts Inst. of Tech. Cambridge
- OSTI ID:
- 6307364
- Journal Information:
- IEEE Trans. Electron Devices; (United States), Journal Name: IEEE Trans. Electron Devices; (United States) Vol. ED-28:11; ISSN IETDA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Impact of carrier wafer on etch rate, selectivity, morphology, and passivation during GaN plasma etching
Reactive sputter etching of Si, SiO/sub 2/, Cr, Al, and other materials with gas mixtures based on CF/sub 4/ and Cl/sub 2/
Related Subjects
360603 -- Materials-- Properties
42 ENGINEERING
420800* -- Engineering-- Electronic Circuits & Devices-- (-1989)
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHROMIUM
DEPTH
DIMENSIONS
ELEMENTS
ETCHING
FABRICATION
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
MAGNESIUM COMPOUNDS
MAGNESIUM FLUORIDES
MASKING
METALS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
SEMICONDUCTOR DEVICES
SEMIMETALS
SILICA
SILICON
SILICON COMPOUNDS
SILICON OXIDES
SURFACE FINISHING
TRANSITION ELEMENTS