| 摘要 |
PROBLEM TO BE SOLVED: To uniformly planarize an insulating film in the case where the insulating film is formed on a pattern having steps and then is planarized. SOLUTION: Trenches 3 are formed in a Si substrate 1 by using a SiN film 2 having openings in the device isolating regions of the Si substrate 1 as a mask. An oxide film 4 is formed on the Si substrate 1 such that it is buried in the trench 3. Next, recesses 6 are formed in the oxide film 4 by using a photoresist having a pattern reverse to the above pattern as a mask. Here, the depth of the recesses 6 is made larger than that of recesses 5 formed in the oxide film 4 at the trench 3. Then, the oxide film 4 is planarized by polishing protrusions 8 of the oxide film 4. The difference in depth between the recesses 6 and the recesses 5 can compensate a difference in polishing speed to uniformly planarize the oxide film 4.
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