Method of bonding a semiconductor device to a support substrate
A method according to embodiments of the invention includes providing a wafer of semiconductor devices grown on a growth substrate. The wafer of semiconductor devices has a first surface and a second surface opposite the first surface. The second surface is a surface of the growth substrate. The method further includes bonding the first surface to a first wafer and bonding the second surface to a second wafer. In some embodiments, the first and second wafer each have a different coefficient of thermal expansion than the growth substrate. In some embodiments, the second wafer may compensate for stress introduced to the wafer of semiconductor devices by the first wafer.
1. A method comprising:
providing a wafer comprising light-emitting devices on a growth substrate, the wafer comprising a first surface and a second surface opposite the first surface, the first surface comprising at least portions of the light-emitting devices and the second surface being a surface of the growth substrate;
bonding the first surface of the wafer to a support wafer at a first above room temperature bonding temperature;
bonding the second surface of the wafer to a stress-compensating wafer at a second above room temperature bonding temperature to form a bonded stack comprising the wafer, the support wafer and the stress-compensating wafer, the support wafer and the stress-compensating wafer having the same thickness and being formed from the same material; and
allowing the bonded stack to cool to room temperature.
2. The method of claim 1 , further comprising removing the stress-compensating wafer after the bonded stack is cooled.
3. The method of claim 1 , wherein the bonding the first surface of the wafer to the support wafer and the bonding the second surface of the wafer to the stress-compensating wafer are performed simultaneously.
4. The method of claim 1 , wherein the thickness of the support wafer and the stress-compensating wafer is between 100 μm and 3 mm.
5. The method of claim 1 , wherein the support wafer and the stress-compensating wafer are formed from silicon.
6. The method of claim 1 , wherein the bonding the first surface of the wafer to the support wafer and the bonding the second surface of the wafer to the stress-compensating wafer are performed at different times.