MOUNTING OF SEMICONDUCTOR-ON-DIAMOND WAFERS FOR DEVICE PROCESSING

1 . A method of mounting a semiconductor-on-diamond wafer on a carrier substrate, the method comprising:

disposing a semiconductor-on-diamond wafer on an optical flat, the semiconductor-on-diamond wafer including a diamond layer and a semiconductor layer and arranged so that the semiconductor layer faces the optical flat;

disposing an adhesive layer on the diamond layer of the semiconductor-on-diamond wafer;

disposing a carrier substrate on the adhesive layer, the carrier substrate including a layer having a lower coefficient of thermal expansion (CTE) than diamond;

pressing the carrier substrate against the optical flat and bonding the carrier substrate to the semiconductor-on-diamond wafer to form a semiconductor-on-diamond-on carrier substrate wafer while the carrier substrate is pressed against the optical flat; and

separating the semiconductor-on-diamond-on-carrier substrate wafer from the optical flat.

2 . A method according to claim 1 , wherein, after the step of separating the semiconductor-on-diamond-on-carrier substrate wafer from the optical flat, the semiconductor-on-diamond-on-carrier substrate wafer has the following characteristics:

a total thickness variation of no more than 40 μm;

a wafer bow of no more than 100 μm; and

a wafer warp of no more than 40 μm.

3 . A method according to claim 1 , wherein the step of bonding includes curing the adhesive layer at a temperature between 10° C. and 40° C.

4 . A method according to claim 1 , wherein the adhesive layer includes a UV glue that is cured when exposed to UV light and the step of bonding includes exposing UV light to the adhesive layer.

5 . A method according to claim 1 , wherein the adhesive includes a thermal release adhesive material, further comprising:

heating the thermal release adhesive material to thereby release the carrier substrate from the semiconductor-on-diamond wafer.

6 . A method according to claim 1 , wherein the adhesive includes a polymer adhesive material and the step of boding includes curing the adhesive by heating.

7 . A method according to claim 1 , wherein the carrier substrate comprises an additional layer having a higher CTE than diamond.

8 . A method according to claim 7 , wherein the additional layer having a higher coefficient of thermal expansion (CTE) than diamond is formed of silicon.

9 . A method according to claim 7 , wherein an adhesive layer is provided between the layer having a lower CTE than diamond and the additional layer having a higher CTE than diamond.

10 . A method according to claim 1 , further comprising:

disposing a thermal release tape between the semiconductor layer of the semiconductor-on-diamond wafer and the optical flat.

11 . A method according to claim 1 , further comprising:

disposing a protective coating layer on the semiconductor layer of the semiconductor-on-diamond wafer.

12 . A method according to claim 1 , further comprising:

disposing a thermal release adhesive layer between the carrier substrate and the semiconductor-on-diamond wafer.

13 . A method of fabricating semiconductor device structures, comprising:

fabricating one or more semiconductor device structures on the semiconductor layer of the semiconductor-on-diamond-on-carrier substrate wafer formed according the method of claim 1 while maintaining the semiconductor-on-diamond-on-carrier substrate wafer at a device fabrication temperature at which bonding of the carrier substrate and semiconductor-on-diamond wafer is maintained; and

releasing the carrier substrate from the semiconductor-on-diamond wafer after fabrication of the one or more semiconductor device structures by heating the semiconductor-on-diamond-on-carrier substrate wafer to a temperature in excess of the device fabrication temperature such that bonding of the carrier substrate and semiconductor-on-diamond wafer is broken.

14 . A semiconductor-on-diamond-on-carrier substrate wafer, comprising:

a semiconductor-on-diamond wafer having a diamond side and a semiconductor side;

a carrier substrate disposed on the diamond side of the semiconductor-on-diamond wafer and including at least one layer having a lower coefficient of thermal expansion (CTE) than diamond; and

an adhesive layer disposed between the diamond side of the semiconductor-on-diamond wafer and the carrier substrate to bond the carrier substrate to the semiconductor-on-diamond wafer,

wherein the semiconductor-on-diamond-on-carrier substrate wafer has the following characteristics:

a total thickness variation of no more than 40 μm;

a wafer bow of no more than 100 μm; and

a wafer warp of no more than 40 μm.

15 . A semiconductor-on-diamond-on-carrier substrate wafer according to claim 14 , wherein the carrier substrate comprises a layer having a higher coefficient of thermal expansion (CTE) than diamond.

16 . A semiconductor-on-diamond-on-carrier substrate wafer according to claim 14 , further comprising:

a thermal release adhesive layer disposed between the carrier substrate and the semiconductor-on-diamond wafer.

17 . A semiconductor-on-diamond-on-carrier substrate wafer according to claim 14 , wherein the adhesive layer includes a UV glue that is cured by UV light.

18 . A semiconductor-on-diamond-on-carrier substrate wafer according to claim 14 , further comprising:

a protective coating layer disposed on the semiconductor side of the semiconductor-on-diamond wafer.

19 . A semiconductor-on-diamond-on-carrier substrate wafer according to claim 14 , wherein the semiconductor-on-diamond-on-carrier substrate wafer meets the characteristics for total thickness variation, wafer bow, and wafer warp over a diameter of at least 50 mm, 75 mm, 100 mm, or 150 mm.

20 . A semiconductor-on-diamond-on-carrier substrate wafer according to claim 14 , wherein the semiconductor-on-diamond wafer incudes gallium nitride.