Patent attributes
A contact hole formation method includes a process of depositing a BPSG film 4 on a semiconductor substrate 1 on which transistors are formed, a process of planarizing the BPSG film 4, a process of depositing a dielectric film 5 on the BPSG film 4, and a process of forming contact holes 8 through the BPSG film 4 and the dielectric film 5 so as to reach the semiconductor substrate 1, in a case in which gate electrodes are densely formed in some areas and sparsely formed in other areas. The above-described contact hole formation method allows a thickness of the BPSG film 4 to be uniform irrespective of the density of the gate electrodes, whereby an etching rate becomes uniform over the entire area of the semiconductor device. Thus, it is possible to form contact holes having minimized variations in a contact resistance and a value of leakage current.
