Method using laser irradiation for the production of atomically clean crystalline silicon and germanium surfaces

Patent · Tue Sep 29 00:00:00 EDT 1981

OSTI ID:5587349

Ownby, G W; White, C W; Zehner, D M

This invention relates to a new method for removing surface impurities from crystalline silicon or germanium articles, such as off-the-shelf p- or n-type wafers to be doped for use as junction devices. The principal contaminants on such wafers are oxygen and carbon. The new method comprises laser-irradiating the contaminated surface in a non-reactive atmosphere, using one or more of q-switched laser pulses whose parameters are selected to effect melting of the surface without substantial vaporization thereof. In a typical application, a plurality of pulses is used to convert a surface region of an off-the-shelf silicon wafer to an automatically clean region. This can be accomplished in a system at a pressure below 10-8 torr, using q-switched ruby-laser pulses having an energy density in the range of from about 60 to 190 mw/c

• Assignee: Department of Energy
• Patent Number(s): US 4292093
• OSTI ID: 5587349
• Resource Relation: Patent File Date: Filed date 28 Dec 1979; Other Information: PAT-APPL-108199
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
LASER RADIATION
USES
SEMICONDUCTOR JUNCTIONS
SURFACE CLEANING
CRYSTAL DOPING
IMPURITIES
PULSED IRRADIATION
Q-SWITCHING
RUBY LASERS
CLEANING
ELECTROMAGNETIC RADIATION
IRRADIATION
JUNCTIONS
LASERS
RADIATIONS
SOLID STATE LASERS
SURFACE FINISHING
420800* - Engineering- Electronic Circuits & Devices- (-1989)
420300 - Engineering- Lasers- (-1989)