The Research of the KOH/Alcohol Etchant System in Wet Etching of Monocrystal Silicon

• Main Authors: Wen-June Cho, 邱文俊
• Other Authors: Wei-Kuo Chin
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/6qun6c

博士 === 國立清華大學 === 化學工程學系 === 92 === Abstract The study is mainly to discuss the influence of alcohol moderator on the different silicon crystalline plane, when the alcohol moderator was added into the KOH solution. Two types of alcohols were added into the KOH solution, one OH group alcohol and multi OH group alcohol. The etching rates of silicon (100) plane and (110) plane depended on the conditions of temperature, KOH concentration and alcohol concentration. At the condition of the highest etching rate, it discussed the development of circular concave of (100) silicon and (110) silicon. At the same time, it discussed the development of square convex of (100) silicon mesa under the condition of the highest etching rate for the design of convex compensation. It was found that the addition of alcohol had no influence on the etching rate of silicon (100) plane, but, significantly affected the etching rate of silicon (110) plane. For the high temperature etching and the smooth of the etched silicon (100) plane, some alcohols can make the etched silicon (100) plane smooth and produce no hillocks. By observing the development of the corner of the square convex, the highest etching rate of the convex corner undercut is (211) plane. The most reduction of the etching rate of (211) plane is at the KOH/1-pentanol etchant system. In the other way, the reduction of the (100) plane area gradually becomes less with the increase of the molecular chain length of alcohol. At the KOH/1-pentanol etchant system, the reduction ratio of the (100) plane area is least.