A new Wafer Treatment Cell for control of solution based thin film processing for applications in microelectronics

This research introduces a new type of wafer processing system called a wafer treatment cell (WTC) which is similar to a spin-coating system but with advanced functionality. The Wafer Treatment Cell is used primarily to facilitate control of solution based thin-film processing. In a typical spin coating system one can use a dropper and spin coat a polymer (e.g. photo resist) on a semiconductor wafer and then take the wafer to a hotplate for heat treatment. This paper introduces advanced functionality to the spin-coating system which includes heat treatment and an applied electromagnetic field in a single station. This allows for real time processing of the temperature and applied electromagnetic field with closed loop feedback systems while it is spin-coating the thin film polymer. Additionally there are gas inlets for atmospheric condition control (e.g. introducing a nitrogen gas while processing) and a gas outlet that is monitored for flow and byproducts. The use of a black-body radiator as the heat source enabled individual crystals to be excited to obtain different overall geometries. The wafer treatment cell was constructed of commercial off the shelf (COTS) items for significantly less than commercial spin coating only systems. The WTC can handle wafers from 1" up to 4" with rotational speeds from 10 rpm up to 5000 rpm. It can also control the wafer temperature up to 500 degrees C with a gas flow up to 100 cm³/min.