NOVELTY - A microelectronic layer is plasma etched by a two-step plasma etch method. The first method uses a first detector (22), which is optimized to measure a thickness of the microelectronic layer. The first detector controls the etching to stop prior to reaching the substrate (10). The second plasma etch method uses a second detector that controls the etching to stop on the substrate.    USE - For plasma etching microelectronic layers during integrated circuit microelectronic fabrications, ceramic substrate microelectronic fabrications, solar cell optoelectronic microelectronic fabrications, sensor image array optoelectronic microelectronic fabrications, and display image array optoelectronic microelectronic fabrications (all claimed).    ADVANTAGE - The method optimally etch microelectronic layers while simultaneously providing accurate endpoint detection during the process.    DETAILED DESCRIPTION - Plasma etching of microelectronic layer involves:    (a) providing a substrate having a microelectronic layer;    (b) etching the microelectronic layer while employing a first plasma etch method to partially etch microelectronic layer; and    (c) etching the partially etched microelectronic layer while using a second plasma etch method.    The first plasma etch method uses a detector, which is optimized to measure a thickness of the microelectronic layer. The first detector controls the etching to stop prior to reaching the substrate. The second plasma etch method uses a second detector. The second detector controls the etching to stop on the substrate. An over etching step is afterwards carried to clearly remove microelectronic dielectric layer residue to form a completely etched microelectronic layer.    DESCRIPTION OF DRAWING(S) - The figure shows a first plasma etching step during formation of gate electrode.    Substrate (10)    Gate dielectric layer (14)    Partially etched blanket gate electrode material layer (16')    Photoresist layer (18)    First detector (22)