Method to improve crystalline regrowth
The migration of dislocations into pristine single crystal material during crystal growth of an adjacent conductive strap is inhibited by a conductive barrier formed at the interface between the layers. The conductive barrier may be formed by implanting carbon impurities or depositing Si:C layer that inhibits dislocation movement across the barrier layer, or by forming a passivation layer by annealing in vacuum prior to deposition of amorphous Si to prevent polycrystalline nucleation at the surface of single crystalline Si, or by implanting nucleation promoting species to enhance the nucleation of polycrystalline Si away from single crystalline Si.
1. A method of forming a semiconductor device comprising:
forming an electrode in a semiconductor substrate, the semiconductor substrate
including a single crystal region;
forming a conductive barrier layer by depositing a layer comprising carbon, germanium or phosphorus over at least one of the electrode and the single crystal region; and
forming a conductive strap to electrically connect the electrode with the single crystal region, wherein the conductive strap is formed over the conductive barrier layer, wherein forming the conductive barrier layer comprises epitaxially depositing a layer of carbon-doped silicon.
2. The method of claim 1 , wherein the conductive strap comprises polycrystalline silicon.
3. The method of claim 1 , wherein the electrode comprises polycrystalline silicon.