Patent ID: 8623740
Filing Date: 2014-01-07
Classification: H01L

Abstract:
1. A method for reducing defects at a bonding interface when producing a structure having an ultra thin buried oxide (UTBOX) layer, which comprises: assembling donor and receiver substrates at a bonding interface wherein at least one of the two substrates includes an insulating layer with the insulating layer(s) positioned between the substrates and having a total thickness of less than 50 nm; conducting a first heat treatment for reinforcing the assembly at a temperature below 400° C., with the first heat treatment carried out during or after the assembling; conducting a second heat treatment at a temperature above 900° C. after the first heat treatment; and controlling exposure time of the assembly at temperatures between 400° C. and 900° C. to less than 1 minute to reduce defects at the bonding interface, wherein the substrates are assembled by molecular bonding and the method comprises ramping the heating temperature between the first and second heat treatments at a rate of above 10° C./s.