Patent ID: 8754505

Claim:
A method of producing a heterostructure that comprises bonding a bonding surface of at least one first substrate having a first thermal expansion coefficient directly onto a bonding surface of a second substrate having a second thermal expansion coefficient, with the first thermal expansion coefficient being different from the second thermal expansion coefficient, the method further comprising, prior to bonding: forming trenches in the bonding surfaces of both the first and second substrates; filling the formed trenches with a filling material having a third thermal expansion coefficient that has a value that is between the first and second thermal expansion coefficients in order to reduce deformations or strains that would otherwise be observed during heat treatments of bonded substrates that do not include such filled trenches with the filling material also deposited over the bonding surfaces of the first and second substrates; and planarizing the filling material to bonding to remove the filling material from the bonding surfaces but not from the trenches.