Abstract: An exhaust gas treatment apparatus for treating exhaust gas generated in semiconductor manufacturing processes. It includes a main pipe, a gas vortex means, a water vortex means, an U pipe and a discharge pipe. The main pipe transforms the exhaust gases to waste powder which are discharged out through the U pipe and the discharge pipe. The gas vortex means and water vortex means are located below the main pipe for generating annular and even downward gas flow and water flow at the outlet of the main pipe for preventing reflux of waste powder from entering into the main pipe. Waste powder thus won't deposit around the outlet. Scraper in the main pipe won't be stuck or deformed. Waste powder may be discharged out through the U pipe and discharge pipe smoothly and efficiently.
Abstract: A method of fabricating kink-effect-free shallow trench isolations is presented in this invention. First, a layer of silicon oxide and a layer of polysilican are sequentially deposited on a substrate, and then shallow trenches are formed, next thermal oxidation is performed to grow a passivation oxide layer on the exposed silicon, and then, a dielectric layer is formed to fill into the shallow trench. Finally, the dielectric layer on the active area is removed by using chemical mechanical polishing and the polysilicon layer provides for the etching end point. The level of shallow trench is higher than the level of active area as soon as stop polishing, because the polysilicon layer is polished faster than dielectric layer. It provides the passivation oxide on the sidewall of shallow trench to form spacers of the active area after removing the polysilicon of active area. It can provide a perfect shallow trench after an oxidation and etching process to avoid the kink effect.
Type:
Grant
Filed:
November 30, 1998
Date of Patent:
November 21, 2000
Assignee:
United Microelectronics Inc.
Inventors:
Lu-Min Liu, Hsi-Chieh Chen, Ping-Ho Lo, Sheng-Hao Lin