Forming method of element isolation region

Abstract

Abstract PURPOSE:To isolate an electrically stable fine element with a flat plane by growing a vitrified silicon oxide film on a thermal oxide film formed on the surface of a silicon single crystal substrate to which a groove is shaped, burying the bottom of the groove through heat treatment at a high temperature, growing a silicon oxide film on the surface containing the groove and removing the silicon oxide film while leaving its one part. CONSTITUTION:A groove 2 for isolating an element is formed on the surface of a silicon single crystal substrate 1 through anisotropic etching. The surface of the silicon single crystal substrate 1 to which the groove 2 is shaped is thermally oxidized to form a thermally oxidized silicon oxide film 3. A vitrified silicon oxide film containing boron and/or phosphorus, a PSG film or a BPSG film 4, is grown on the surface of the thermally oxidized silicon oxide film 3. The element is thermally treated at a high temperature, and the PSG film or the BPSG film 4 is fluidized to completely bury the groove 2 consisting of silicon. A silicon oxide film 6 to which boron or phosphorus is not doped is grown on the surface of the substrate 1 in the vapor phase so as to completely bury the shallow groove. The silicon oxide film 6 is etched to leave a silicon oxide film 7 only in the upper section of the groove.

Inventors

• 👤 Keimei Mikoshiba
• 👤 御子柴　啓明

Bibliographic Details