Method for forming doped area on insulating layer covered with silicone

The present invention has provided a forming method of doping area on silicon on insualtor SOI, of which the silicon on insulator consists of a dielectric layer and a silicon layer set on the dielectric layer. The method is to form a shallow treach isolation at a preset position of the silicon layer and to let it pass through for reaching the dielectric layer first and then to utilize the diffusion method to tend in ions for forming N-well or P-well doping area at the first zone on the silicon layer as well as the use the same manner to form N-well or P-well doping area at the second zone on the silicon layer, at last to grow a epitaxy layer of 200 angstrom thickness by utilizing molecular beam epitaxy growth, liquid phase epitaxy growth or gas phase epitaxy growth.