| 摘要 |
PROBLEM TO BE SOLVED: To prevent deterioration of the charge holding characteristic and isolation characteristic of a semiconductor device, by preventing the contamination of a thermally oxidized film with heavy metals at the time of forming a grooved capacitance element or performing element separation. SOLUTION: After a groove 103 is formed into a silicon substrate 101 having a gettering site 100 by dry etching, a first thermally oxidized film 105 is formed on the surface of the substrate 101 including the groove 103. Then, after the film 105 is removed by wet etching, contaminating heavy metal elements existing on the surface of the groove 103 are captured in the gettering site 100 in the substrate 101 by performing a heat treatment in a reducing atmosphere. After cleaning the surface of the groove 103 in such a way, a second thermally oxidized film 108 which is used for forming a capacitance element or for performing isolation is formed. |
