Integrated thermoelectric cooler formed on the backside of a substrate

The present invention provides a structure and a method of fabricating a thermoelectric Cooler directly on the backside of a semiconductor substrate. The thermoelectric (TE) cooler (thermoelectric cooler) disperses heat from an integrated circuit (IC) that is formed on the front-side of the silicon substrate. Spaced first bonding pad holes 28 are formed in the backside of a substrate that expose bonding pads 24. Second holes 32 are formed between the spaced first bonding pad holes 28. A first insulating layer 34 is formed over the backside of the substrate, but not over the bonding pad 24. A metal layer is formed lining the first bonding pad holes 28. A polysilicon layer 46 is formed over the surface of the backside of the substrate in the second holes. The polysilicon layer is implanted thereby forming alternating adjacent N and P doped sections 46p 46n in the second holes. The adjacent N and P doped polysilicon sections 46n 46p are electrically connected to the bonding pads 24 by the metal layer 38.