Method of forming vias in a GaN/diamond wafer
Wafers including a diamond layer and a semiconductor layer having III-Nitride compounds and methods for fabricating the wafers are provided. A nucleation layer, at least one semiconductor layer having III-Nitride compound and a protection layer are formed on a silicon substrate. Then, a silicon carrier wafer is glass bonded to the protection layer. Subsequently the silicon substrate, nucleation layer and a portion of the semiconductor layer are removed. Then, an intermediate layer, a seed layer and a first diamond layer are sequentially deposited on the III-Nitride layer. Next, the silicon carrier wafer and the protection layer are removed. Then, a silicon substrate wafer that includes a protection layer, silicon substrate and a diamond layer is prepared and glass bonded to the first diamond layer.
1. A method for processing a semiconductor wafer, comprising:
disposing and patterning a first metal layer on a semiconductor layer of a semiconductor wafer, wherein the semiconductor wafer includes a support layer, a bonding layer, a first diamond layer, an intermediate layer and the semiconductor layer;
drilling one or more holes from the first metal layer toward the support layer to thereby form one or more vias that extend from the first metal layer into the support layer;
disposing a second metal layer on the first metal layer and in a portion of the one or more vias; and
removing the support layer and the bonding layer to expose a surface of the first diamond layer,
wherein the support layer includes a second diamond layer, a silicon substrate, and a protection layer.
2. The method of claim 1 , further comprising:
cleaning the exposed surface of the first diamond layer.
3. The method of claim 1 , further comprising:
disposing a third metal layer on the exposed surface of the first diamond layer and a side surface of the one or more vias, wherein the third metal layer electrically contacts the second metal layer.
4. The method of claim 1 , wherein the protection layer is formed of a material that includes one or more of SiN, poly-Si, Al2O3, AlN and GaN.
5. The method of claim 1 , wherein the bonding layer is formed of glass.
6. The method of claim 1 , further comprising:
prior to the step of disposing and patterning the first metal layer, forming one or more semiconductor devices in the semiconductor layer.
7. The method of claim 6 , wherein the one or more semiconductor devices includes one or more high electron mobile transistors (HEMTs).
8. The method of claim 6 , further comprising:
prior to the step of forming the one or more semiconductor devices in the semiconductor layer, forming the intermediate layer on the semiconductor layer, forming the first diamond layer on the intermediate layer, forming the bonding layer on the first diamond layer, and attaching the support layer to the bonding layer.
9. The method of claim 8 , wherein the semiconductor layer includes a III-Nitride compound.
10. The method of claim 8 , wherein the semiconductor layer includes a GaN layer.
11. The method of claim 10 , further comprising:
forming an additional semiconductor layer on the semiconductor layer on a first side of the semiconductor layer opposite to a second side of the semiconductor layer where the intermediate layer is formed.
12. The method of claim 11 , wherein the additional semiconductor layer includes a III-Nitride compound.
13. The method of claim 12 , wherein the additional semiconductor layer is an AlGaN layer.
14. The method of claim 12 , wherein the additional semiconductor layer is an InAlN layer.