All diamond packaging for wireless integrated micro-systems using ultra-fast diamond growth

Polycrystalline diamond (poly-C) is an excellent packaging material for wireless integrated microsystems (WIMS). An ultra-fast poly-C growth technique is developed to fabricate WIMS packaging panels with built-in interconnects. DRIE is used to etch high aspect ratio channels in Si, which increase the growth area for poly-C. Electrophoresis is used to provide seeding in 2 μm wide Si channels, which are filled with poly-C using microwave plasma CVD. Si is chemically dissolved and another layer of poly-C is grown on the backside of the first layer to fabricate a thick poly-C panel (20 - 100 μm). The experimental results show that this technique can help reduce the fabrication time of poly-C by a factor in the range of 2.75 - 10.5 depending upon the aspect ratio. If the second layer of poly-C is boron doped, it could be used as a built-in interconnect after the surface is polished. An interconnect resistivity as low as 0.0015 Ohm-cm has been achieved.