Annealing process for annealing a structure
The invention relates to a process for annealing a structure that includes at least one wafer, with the annealing process including conducting a first annealing of the structure in an oxidizing atmosphere while holding the structure in contact with a holder in a first position in order to oxidize at least portion of the exposed surface of the structure, shifting the structure on the holder into a second position in which non-oxidized regions of the structure are exposed, and conducting a second annealing of the structure in an oxidizing atmosphere while holding the structure in the second position. The process provides an oxide layer on the structure.
1. A process for annealing a structure that includes at least one wafer, wherein the process comprises:
conducting a first annealing of the structure in an oxidizing atmosphere while holding the structure in contact with a holder in a first position in order to oxidize at least a portion of an exposed surface of the structure;
shifting the structure on the holder into a second position in which non-oxidized regions of the structure are exposed; and
conducting a second annealing of the structure in the oxidizing atmosphere while holding the structure in the second position.
2. The process of claim 1 , wherein the shifting includes rotating the structure through an angle relative to the holder.
3. The process of claim 2 , wherein the angle through which the structure is rotated is between 40° and 90°.
4. The process of claim 1 , wherein the non-oxidized regions of the structure represent regions of contact between the structure and the holder in the first position.
5. The process of claim 1 , wherein the structure is held by the holder in the second position by contact with oxidized regions of the structure.
6. The process of claim 1 , wherein the first and second annealings of the structure in the oxidizing atmosphere provides an oxide layer on the structure.
7. The process of claim 6 , which is conducted to form a uniform oxide layer on the entire surface of the structure.
8. The process of claim 1 , wherein the structure is a heterostructure formed by bonding a first wafer to a second wafer.
9. The process of claim 8 , which further comprises, after the second annealing:
thinning the first wafer; and
chemical trimming the first wafer.
10. The process of claim 1 , wherein the structure is a first wafer and which further comprises forming a heterostructure after the second annealing by bonding the first wafer to a second wafer.
11. The process of claim 10 , which further comprises before bonding the wafers, forming at least one microcomponent in the second wafer.
12. The process of claim 10 , which further comprises annealing the heterostructure for stabilizing the bond between the wafers.
13. The process of claim 12 , which further comprises after conducting the stabilizing annealing:
thinning the first wafer; and
chemical trimming the first wafer.