The Synthesis and CMP Application of Ceria Powder

• Main Authors: Chien-Chih Chiang, 江建志
• Other Authors: Chien-Hsing Hsu
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/96844941521592159325

碩士 === 逢甲大學 === 化學工程學所 === 91 === Abstract As the device feature is gradually shrinking, the quality requirement of abrasive for chemical mechanical polish (CMP) process is stricter. The CMP slurry based on cerium dioxide has higher removal rate, higher selectivity then other kinds of slurry, and was investigate for shallow trench isolation (STI) and inter-layer deposition (ILD). Nanometer-sized particles of cerium oxide have been prepared by precipitation method using ammonium cerium nitrate as a starting material with urea as an additive, followed by the aging process. To increase the particle size, the as-prepared cerium oxides were mixed with ammonium cerium nitrate and then urea was added slowly into the mixed solution. The effects of the seed concentrations, the reactant concentrations, the urea adding rate and the pH values on the crystal growth of cerium oxide, the primary particle size and the secondary size were investigated. We have found that the pH value is crucial to the secondary particle size of the particles. For the CMP process, we prepared some slurries from those obtained cerium oxides to polish silicon oxide and silicon nitride films. The CMP quality is comparable to commercial slurries. The removal rates are about 1300 Å/min and 100 Å/min for silicon oxide and silicon nitride films respectively.