Optical end point detection methods in semiconductor planarizing polishing processes
US5413941A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1994 |
| Grant date | May 9, 1995 |
| Priority date | — |
| Expiry date | Jan 6, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/306
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A semiconductor processing method of detecting polishing end point from a polishing planarization process includes: a) impinging laser light onto an area of an outermost surface of a semiconductor substrate at an angle of incidence of at least 70.degree. from a line normal relative to the substrate (at least 60.degree. for s-polarized light), the impinged laser light predominantly reflecting off the area as opposed to transmitting therethrough; b) measuring intensity of the light reflected off the area; c) polishing the substrate outermost surface; d) repeating step "a" then step "b"; and e) comparing a prior measured intensity of reflected light with a later measured intensity of reflected light to determine a change in degree of planarity of the semiconductor substrate outermost surface as a result of polishing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.