Dielectric isolation of semiconductor substrate surface

Abstract

Abstract PURPOSE:To enable forming of an isolation region of minute width by determining the width of dielectric isolation of a semiconductor substrate in one photolithography process and permitting almost no variation of dimensions in later processes. CONSTITUTION:On a P type Si substrate 21, an N<+> buried region 22, an N type epitaxial layer 23 and an Si3N4 layer 24 are formed. On the film 24, a hole is opened and a groove 25, the depth of which reaches the substrate 21, is formed. Then, a polycrystalline Si film 28 is formed covering the film 24 and a film 27. Next, the film 28 is treated by anisotropic ion etching and left only at the side of the groove 25. Then, when polycrystalline Si is again formed, selective growth occurs using the film 28 at the side of the groove 25 as a nucleus and polycrystalline Si 29 is formed to fill the groove 25. In this method, forming of dielectric isolation region requires no thermal oxidatin process for a long time resulting no crystalline defects due to stress, etc. Since the width of an isolation region is determined by one photolithography process, the isolation region of a minute width can be formed.

Inventors

• 👤 Ichiro Matsuo
• 👤 一郎 松尾

Bibliographic Details