Bacon & Thomas
Method for forming rugged polysilicon capacitor
 The present invention relates to a method for forming rugged polysilicon capacitance electrodes uses for dynamic random access memory processes is disclosed. The method is capable in reducing process time, enhancing yield, and saving production cost. Wherein, the process of the present invention comprises: firstly, a semiconductor wafer is delivered into a low pressure chemical vapor deposition (LPCVD) tube. Herein, a non-doped or doped amorphous silicon layer is deposited on the surface top of electrodes. A rugged polysilicon capacitance is formed on top of the non-doped or doped amorphous silicon layer by using the methods of rising temperature and decreasing pressure. Then, an ion implantation is applied and follows by a wafer cleaning procedure and an annealing process, wherein those procedures are accomplished after the removal of the wafer from LPCVD tube. During the annealing process, the non-doped or doped amorphous silicon layer is transformed into a polysilicon layer under a temperature roughly about 850.degree.C. In particularly, an in-situ phosphorous doped amorphous silicon can be deposited prior to the formation of non-doped amorphous silicon layer, and won't influence the stages that follow. 
Mosel Vitelic Inc.
H Y H
H01L Y10S H01L
additional additional inventional
Ming-Kuan Jui-Ping Ping-Wei
Kao Li Lin