In-situ measurement of deposition on reactor chamber members
US6019000A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 20, 1997 |
| Grant date | Feb 1, 2000 |
| Priority date | — |
| Expiry date | Nov 20, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0422
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system is disclosed that employs ultrasonic waves to perform in-situ measurements to determine the properties of films deposited on substrates in the course of various semiconductor or processing steps. In one embodiment a single transducer excites incident acoustic waves at multiple frequencies that reflect from the films. The reflected waves are received by the same transducer. An analysis system determines the phase shift of the received reflected waves and, based on the phase shift, determines the film properties. Other embodiments employ distinct source and receiving transducers. Embodiments are also disclosed that compensate the measured phase shift for temperature variations in the substrate. In one such system, temperature compensation is performed based on the processing of phase measurements made at multiple frequencies or incidence angles or with multiple ultrasonic modes. The disclosed techniques are equally applicable to determining the degree of erosion of chamber members.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.