APS

The SPTS APS is an etching system built around an inductively coupled plasma based high density plasma source. The SPTS APS was optimized for dielectric etching, including SiO2, SixNy, SiC, Al2O3, and glass materials. The SPTS APS provides independent wafer voltage biasing from the ICP source. The SPTS APS uses electrostatic clamping and loadlock to chamber transfer for single wafer processing. The SPTS APS supports Optical Emission Spectroscopy end point detection and laser reflectometry or interferometry end point detection.^[1][4]

The SPTS APS loads a wafer, clamps it electrostatically, and switches on helium back cooling before etching. The SPTS APS checks wafer cooling with a leak up rate measurement, and the allowed leak up rate must not exceed 200 mtorr per minute. The SPTS APS can monitor etching with an end point detection system, but the end point system operates in monitoring only mode and does not automatically stop the chamber process. The SPTS APS then performs a dechuck step with electrostatic clamping switched off and a low power argon plasma used for charge removal. The SPTS APS can run an automatic cleaning sequence for the chamber and chuck after wafer unload, with cleaning stopped by end point detection.^[1][4]

Dielectric etch tools are used after lithographic patterning to transfer mask features into insulating or structural dielectric layers. Dielectric etch steps commonly feed later stripping, cleaning, deposition, packaging, or release operations depending on the device type. In MEMS and photonic process flows, dielectric plasma etch also shapes glass and related materials for optical, mechanical, and isolation functions.