MANUFACTURE OF SEMICONDUCTOR DEVICE

• Main Author: ARIMOTO YOSHIHIRO
• Format: Patent
• Language: English
• Published: 17.12.1990
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To enhance an electric conductivity, a thermal conductivity and a mechanical strength of a support-side substrate by a method wherein a metal is diffused to the support-side substrate and the support-side substrate is alloyed. CONSTITUTION:An LSI is formed, by using an ordinary process, on an element- side substrate 3 of an SOI-structure substrate composed of the following: a support-side substrate 1 formed by pasting two 6-inch Si wafers where an SiO2 film as an insulating layer 2 has been formed on the surface; the insulating layer 2; and the element-side substrate 3. Copper is vapor-deposited in a thick ness of about 2mum on a support-side substrate 1a whose thickness has been reduced; a metal layer 4 is formed. A heat treatment is executed at 400 deg.C for 10 hr. The copper is diffused to the support-side substrate 1a whose thickness has been reduced; it is alloyed with Si of the support-side substrate 1a; the support-side substrate 1a whose thickness has been reduced becomes an alloy layer 5 of Si and Cu. The alloy layer 5 is lapped down to a thickness of about 0.1mm; an alloy layer 5a whose thickness has been reduced is formed. During this lapping operation, a mechanical strength of the support-side substrate has been enhanced by forming the alloy layer 5; as a result, this substrate is not destroyed.