Semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To thin the thickness of a porous Si oxide film required for complete isolation, and to obtain a FET having high density and operating at high speed by bringing the width of a completely isolated Si island to size in which length at the irreducible minimum of a demand of source and drain layers is added to gate length. CONSTITUTION:A single crystal layer 24 perfectly isolated by a porous SiO2 film 23 is formed to an Si substrate 22, and a single crystal layer 25 on the layer 24 and poly Si 26 on the SiO2 23 are shaped by using SiH4. The surface is isolated by an oxide film 28, and a gate oxide film 27 and an Si gate 29 are formed. When the thickness of the film 23 is represented by T, the thickness of the Si layer 24 t, width thereof W, gate length thereof LP and the alignment accuracy of the gate 29 + or -delta, (2T-2t)>W and W=Lp+2delta (where 0<epsilon<2delta) hold. When Lp is equal to 2mum, delta to 0.5mum and t to 0.5mum, W is equal to 3mum, and approximately 3mum is required as T. Ions are implanted through self-alignment to shape sources 32, 33 and drains 34, 35, an SiO2 film 30 is deposited, openings are bored and electrode wirings 31 are formed. According to the constitution, size W is made smaller than a conventional device, and the thickness T of the porous SiO2 film is thinned extremely, thus obtaining a FET having high density and operating at high speed.

Inventors

• 👤 Kohei Ebara
• 👤 江原　孝平
• 👤 Hideyuki Unno
• 👤 秀之 海野
• 👤 Susumu Muramoto
• 👤 村本　進

Bibliographic Details