Process and apparatus for detecting aberrations in production process operations
US4846928A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1988 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | Jul 22, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32935
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved apparatus and process for detecting aberrations in production process operations is provided. In one embodiment, operations of a plasma etch reactor (10) are monitored to detect aberrations in etching operations. A reference end-point trace (EPT) is defined (62) for the etch process. Regions are defined in the reference end-point trace (70) and characteristics and tolerances for each region are defined (72-80). The etcher is run and an actual EPT is obtained (82) from the running of the etcher. The actual EPT is analyzed to identify proposed regions of the actual EPT (86), and then the proposed regions of the actual EPT are matched with regions of the reference EPT (96). The system employs a series of heuristic functions in matching proposed regions of the actual EPT with regions of the reference EPT. Characteristics of the matched regions of the actual end-point trace are compared (66) with characteristics of the corresponding regions of the reference end-point trace to determine whether aberrations have occurred during the etch process. The invention provides for an improved matching and improved comparison of actual end-point traces with reference end-point traces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.