Texas Instruments Corporation

Steven B Dolins

Bruce E Flinchbaugh

Aditya Srivastava

Thomas Warren Lassiter

Sarma S Gunturi

Jon Reese

Robert L Love

Operations of a plasma etch reactor (10) are monitored to detect aberrations in etching operations. A reference end point trace is defined (62) for the etch process. Regions are defined in the reference end point trace (70) with aid of a dynamic time warping matching function (84) and characteristics and tolerances for each region are defined (72-80). The etcher is run and an actual end point trace is obtained (82) from the running of the etcher. A warping function is constructed (88) between the actual trace and the reference trace. In building the warping function, candidate path segments (100) are constructed according to a minimum cumulative cost function (96). Once the regions of the reference trace and the actual trace has been matched according to an optimum dynamic time warping function path (106), characteristics of the matched regions are compared (66) to determine whether aberrations have occurred during the etch process. In an alternative embodiment, the actual trace (164) is matched to each of a library of reference traces (162,182) by dynamic time warping (166). By determining the best match, a determination can be made whether the actual trace is abnormal (174) or normal (176), and the type of abnormality.

Apparatus and method for production process diagnosis using dynamic time

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.

Process and apparatus for detecting aberrations in production process

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Dallas, TX, United States of America

Steven B Dolins