Patent ID: 6199748
Filing Date: 2001-03-13
Classification: B23K

Abstract:
A method for forming a wafer of a compliant composite substrate, comprising the steps of:a) selecting a first substrate material having a melting point of T.sub.m1 ;b) selecting a second substrate material having a melting point of T.sub.m2 ;c) selecting a joint metal with a melting point of T.sub.m ; whereini) said joint metal and said first substrate material form a first eutectic alloy at a first eutectic temperature T.sub.eu1 while said joint metal and said second substrate material form a second eutectic alloy at a second eutectic temperature T.sub.eu2 ; andii) T.sub.m1 and T.sub.m2 >T.sub.m >T.sub.eu1 and T.sub.eu2 ;d) depositing said joint metal on a side of said first substrate material to form a first intermediate substrate;e) depositing said joint metal on a side of said second substrate material to form a second intermediate substrate;f) forming a substrate pair by combining said first and second intermediate substrates such that said sides of said first substrate material and said second substrate material having said joint metal on them are against each other;g) ramping a temperature of said substrate pair up to at least T.sub.m, whereby said temperature passes through T.sub.eu1 and T.sub.eu2 ; andh) cooling, after step (g), said substrate pair to form said compliant composite substrate.