Epitaxial thinning process

Details Epitaxial thinning process Epitaxial thinning process

1982-04-06

1984-07-31

Kaplan, G. L.

Chemistry: electrical and wave energy

Processes and products

204 56R, 204 376, 324158D, 324158T, C25D 1132

Patent

active

044628714

ABSTRACT:
A method is described for thinning an epitaxial layer (16) of a wafer (12) that is to be used in producing diodes having a specified breakdown voltage and which also facilitates the thinning process. Current is passed through the epitaxial layer, by connecting a current source between the substrate (14) of the wafer and an electrolyte (20) in which the wafer is immersed. When the wafer is initially immersed, the voltage across the wafer initially drops and then rises at a steep rate (from 56 to 58). When light is applied to the wafer the voltage drops (from 60 to 62), and when the light is interrupted the voltage rises again (from 66 to 68). These changes in voltage, each indicate the breakdown voltage of a Schottky diode that could be prepared from the wafer at that time. The epitaxial layer is thinned by continuing to apply current through the wafer while it is immersed and light is applied, to form an oxide film (24) and when the oxide film is thick the wafer can then be cleaned of oxide and the testing and thinning continued. Uninterrupted thinning can be achieved by first forming an oxide film, and then using an electrolyte that dissolves the oxide about as fast as it is being formed, to limit the thickness of the oxide layer.

REFERENCES:
patent: 3117899 (1964-01-01), McLouski
patent: 3250693 (1966-05-01), Amaya
patent: 3658672 (1972-04-01), Norris

Affiliated with

Also associated with

Rating

Epitaxial thinning process does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Epitaxial thinning process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Epitaxial thinning process will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-184425