A Study of Electroless Nickel on a Wafer for

• Main Authors: Tsai Chien-Ying, 蔡建瑩
• Other Authors: E.Y. Wu
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/08248477951399555654

碩士 === 國立臺灣科技大學 === 機械工程系 === 87 === In this research a new approach of electroless nickel deposition on a wafer, using poly (acrylic acid) solution to replace SnCl2 solution as a sensitizer, was conducted on the silicon wafer. Analyzed parameters are the concentration of poly(acrylic acid) solution and the concentration; temperature, and pH value of the PdCl2 solution(the activator ), all of which affect the electroless nickel deposition rate. X-ray diffraction analysis, SEM/EDS, SERS and AFM were used to characterize the morphology and the chemical revolution occurred on the wafer during the electroless deposition process. Experimental results show that the minimum concentration of poly(acrylic acid) required for a successful electroless nickel deposition process is 0.1wt%. The deposition rate increase with increasing the concentration of poly(acrylic acid)up to 2.5wt%, above which a increase of concentration has little effect on the deposition rate. The highest deposition rate can be achieved using the PdCl2 solution at 0.1wt% with 5.5 pH value operating at 550C. The concentration of complex agent in the deposition bath can also affect the nickel deposition rate, experi-mental results show that the lactic acid is the must potent ome. Result of X-ray diffraction analysis show that a nickel-phoshor film film is deposition on the wafer. Obsvervation under SEM and AFM reveal that the deposition film can truly duplicate the surface morphology of the wafer, a continuous film is formed over the troughs of 1~2μm wide. The results of SERS show that the palladium ion is bonded to the carboxylic acid group becoming carboxylate sate.