Semiconductor device and its manufacture

Abstract

Abstract PURPOSE:To achieve a high density integration capable of fine multi-layer wiring, by laying a BPSG film in the groove to constitute a separation region where the BPSG film makes no air gap in the groove and its surface is kept flat. CONSTITUTION:On the surface of the P-type silicon substrate 1, an N-type buried collector layer 2 is formed, on which an N-type epitaxial layer 3 is formed. The groove 4 is formed reaching a silicon substrate 1 through the layers 2 and 3. Said groove 4 is almost vertical, whose width and depth are 1.0Xm and 5Xm, respectively. On the surface of an epitaxial layer 3 and the inner surface of the grove 4, thermal oxidation films 5 and 6 are formed, respectively. A BPSG film 7 is buried in a manner in which it makes no air gap in the groove 4 and its upper surface keeps a flat plane. In this manufacturing method, a polysiloxane solution containing boron and phosphorus as an impurity is spread on the substrate by rotation, and the spread BPSG film is subjected to a reflow thermal treatment at a temperature 850 deg.C or higher.

Inventors

• 👤 Masahiko Nakamae
• 👤 正彦 中前

Bibliographic Details