Synthetic diamond heat spreaders
A synthetic diamond heat spreader, the synthetic diamond heat spreader comprising: a synthetic diamond material including a surface layer having a 13 C content of less than a natural isotopic abundance (1.1%) and a support layer which is thicker than the surface layer and which has an isotopic abundance of 13 C which is closer to the natural isotopic abundance than the surface layer, wherein at least 50% of a thickness of the synthetic diamond material is formed of the support layer; and a non-diamond thermal transfer layer disposed in contact with the surface layer of the synthetic diamond material for transferring heat into the surface layer.
1. A semiconductor device component comprising:
a compound semiconductor layer; and
synthetic diamond heat spreader, wherein the synthetic diamond heat spreader comprises:
a synthetic diamond material including a surface layer having a 13 C content of less than a natural isotopic abundance (1.1%) and a support layer which is thicker than the surface layer and which has an isotopic abundance of 13 C which is closer to the natural isotopic abundance than the surface layer, wherein at least 50% of a thickness of the synthetic diamond material is formed of the support layer; and
a non-diamond thermal transfer layer disposed in contact with the surface layer of the synthetic diamond material for transferring heat into the surface layer from the compound semiconductor layer which is disposed on the non-diamond thermal transfer layer,
wherein the surface layer has a thickness of no more than 20 μm, and
wherein a distance between the surface layer of the synthetic diamond material and the compound semiconductor layer is no more than 3 μm.
2. A semiconductor device component according to claim 1 , wherein the 13 C content of the surface layer is less than 1.0%, 0.8%, 0.6%, 0.4%, 0.2%, 0.1%, 0.05%, or 0.01%.
3. A semiconductor device component according to claim 1 , wherein the support layer has a natural isotopic abundance of 13 C.
4. A semiconductor device component according to claim 1 , wherein the surface layer has a thickness of no more than 10 μm, 8 μm, 6 μm, 4 μm, 2 μm, or 1 μm.
5. A semiconductor device component according to claim 1 , wherein the support layer has a thickness of no less than 10 μm, 30 μm, 50 μm, 70 μm, 90 μm, 110 μm, 130 μm, 150 μm, 180 μm, 200 μm, 250 μm, 350 μm, 500 μm, or 1000 μm.
6. A semiconductor device component according to claim 1 , wherein the surface layer has an average thermal conductivity no less than 400 W/mK, 600 W/mK, 800 W/mK, 1000 W/mK, 1200 W/mK, 1400 W/mK, 1600 W/mK, 1800 W/mK, 2000 W/mK, 2200 W/mK, 2400 W/mK, 2600 W/mK, 2800 W/mK, or 3000 W/mK.
7. A semiconductor device component according to claim 1 , wherein the support layer has an average thermal conductivity of no less than 400 W/mK, 600 W/mK, 800 W/m K, 1000 W/mK, 1200 W/mK, 1400 W/mK, 1500 W/mK, 1800 W/mK, or 1900 W/mK.
8. A semiconductor device component according to claim 1 , wherein at least 90% of the thickness of the synthetic diamond material is formed of the support layer.
9. A semiconductor device component according to claim 1 , wherein the synthetic diamond material is CVD synthetic diamond material.
10. A semiconductor device component according to claim 1 , wherein the synthetic diamond material is polycrystalline CVD synthetic diamond material.
11. A semiconductor device component according to claim 10 , wherein the synthetic diamond material has at least one of: a largest linear dimension of at least 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, or 140 mm; and a thickness of at least 0.2 mm, 0.3 mm, 0.5 mm, 0.75 mm, 1.0 mm, 1.3 mm, 1.5 mm, or 2.0 mm.
12. A semiconductor device component according to claim 1 , wherein the synthetic diamond material is single crystal CVD synthetic diamond material.
13. A semiconductor device component according to claim 1 , wherein the synthetic diamond material has sufficient mechanical strength that it can form a free-standing wafer.
14. A semiconductor device component according to claim 1 , wherein the synthetic diamond material has at least one of:
an absorption coefficient measured at room temperature of ≦0.2 cm −1 , ≦0.1 cm −1 , or ≦0.05 cm −1 at 10.6 μm; and
a dielectric loss coefficient tan δ measured at room temperature at 145 GHz of ≦2×10 −4 , ≦10 −4 , ≦5×10 −5 , ≦10 −5 , ≦5×10 −6 , or ≦10 −6 .
15. A semiconductor device component according to claim 1 , wherein a distance between the surface layer of the synthetic diamond material and the compound semiconductor layer is no more than 1 μm, 100 nm, or 50 nm.
16. A semiconductor device component according to claim 1 , wherein the compound semiconductor layer is formed of a nitride.