Patent ID: 11876015
Assignee: SOITEC
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method for transferring a useful layer to a carrier substrate, comprising the following steps:
a) providing a donor substrate including a buried weakened plane, the useful layer being delimited by a front face of the donor substrate and the buried weakened plane;
b) providing a carrier substrate;
c) joining the donor substrate, by its front face, to the carrier substrate along a bonding interface so as to form a bonded structure;
d) annealing the bonded structure to apply a weakening thermal budget thereto and to bring the buried weakened plane to a defined level of weakening, the anneal reaching a maximum hold temperature; and
e) initiating a splitting wave in the buried weakened plane by applying a stress to the bonded structure, the splitting wave propagating in a self-sustained manner along the buried weakened plane to result in the useful layer being transferred to the carrier substrate;
wherein the initiation in step e) takes place when the bonded structure is experiencing a thermal gradient defining a hot region and a cool region of the bonded structure, the stress being applied locally in the cool region, and the hot region experiencing a temperature lower than the maximum hold temperature.