US 11,056,340 B2
Direct bonding process
Frank Fournel, Villard-Bonnot (FR); and Frederic Mazen, Saint-Egreve (FR)
Assigned to Commissariat a l'energie atomique et aux energies alternatives, Paris (FR)
Filed by Commissariat a l'energie atomique et aux energies alternatives, Paris (FR)
Filed on Dec. 3, 2018, as Appl. No. 16/207,828.
Claims priority of application No. 17 61829 (FR), filed on Dec. 8, 2017.
Prior Publication US 2019/0214258 A1, Jul. 11, 2019
Int. Cl. H01L 21/18 (2006.01); H01L 21/762 (2006.01); H01L 21/265 (2006.01); H01L 21/324 (2006.01); H01L 21/20 (2006.01)
CPC H01L 21/187 (2013.01) [H01L 21/26506 (2013.01); H01L 21/324 (2013.01); H01L 21/76254 (2013.01); H01L 21/2007 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A process for attaching a first substrate to a second substrate by direct bonding, the process comprising:
a) providing the first and second substrates, each comprising a first surface and an opposite second surface;
b) bonding the first substrate to the second substrate by direct bonding between the first surfaces of the first and second substrates, b) being carried out under a first gaseous atmosphere having a first relative humidity level denoted by φ1; and
c) applying a thermal annealing treatment to the bonded first and second substrates at a thermal annealing temperature of between 20° C. and 700° C., c) being carried out under a second gaseous atmosphere having a second humidity level denoted by φ2, satisfying φ2≥φ1, wherein
the bonded first and second substrates are kept, after b) and during execution of c), under an atmosphere having a humidity level higher than or equal to φ1 such that adhesion energy of the first surfaces of the first and second substrates is homogenized.