| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of forming stable contact holes, free from the density of gate electrodes. SOLUTION: This method of forming contact holes comprises the steps of: depositing a boron phosphous-doped silicon glass (BPSG) film on a semiconductor substrate on which a transistor is formed, flattening the BPSG film, depositing an insulating layer on the BPSG film, and forming the contact holes which reaches the semiconductor substrate through the BPSG film and the insulating layer, in the cases where gate electrodes are dense in some areas and sparse in other areas. This procedure allows an etching rate between contact holes to be uniform since a BPSG thickness from the substrate becomes uniform regardless of the density of gate electrode formation regions, and the contact holes having a reduced fluctuation in contact resistances and leakage current values to be formed. COPYRIGHT: (C)2008,JPO&INPIT
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