Abstract: 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.

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.