Patent ID: 6090689
Filing Date: 2000-07-18
Classification: H01L

Abstract:
A method for forming an isolated silicon layer on a silicon containing substrate having a major surface comprising the steps of:heating said silicon containing substrate to a first temperature,first implanting oxygen ions at a first energy corresponding to a depth for formation of a desired isolated silicon layer thickness through said major surface of said silicon containing substrate at a dose in the range from about 1.times.10.sup.16 cm.sup.-2 to about 2.times.10.sup.18 cm.sup.-2,cooling said silicon containing substrate below 200.degree. C.,second implanting oxygen ions at a second energy through said major surface of said silicon containing substrate at a temperature below 200.degree. C. at a dose in the range from about 1.times.10.sup.14 cm.sup.-2 to about 1.times.10.sup.16 cm.sup.-2 to form an amorphous silicon layer containing both dissolved and precipitated oxygen within said amorphous layer,first annealing said amorphous silicon layer above room temperature to form polycrystalline silicon, andsecond annealing said polycrystalline silicon in the range from 1100.degree. C. to below the melting temperature to form a continuous oxide layer whereby said polycrystalline silicon functions to provide sites for nucleating oxide growth and paths for rapid diffusion of oxygen along its grain boundaries.