Patent ID: 6037202
Filing Date: 2000-03-14
Classification: H01L

Abstract:
A method for growing a layer of material, the method comprising the steps of:providing a substrate having an exposed surface;placing the substrate into a chamber at a low temperature;removing oxygen from the chamber;exposing the substrate simultaneously to a first growth gas and an etching gas wherein: (1) a growth rate of the exposed surface due to the first growth gas is less than an etch rate of the exposed surface due to the etching gas when the chamber is set at the low temperature, whereby material is etched from the exposed surface when the chamber is at the low temperature; and (2) a growth rate of the exposed surface due to the first growth gas is greater than an etch rate of the exposed surface due to the etching gas when at a high temperature greater than the low temperature so that material is grown on the exposed surface when the chamber is set to the high temperature;ramping the temperature of the chamber from the low temperature to the high temperature over a first period of time while both the etchant gas and the first growth gas are present within the chamber whereby the etch rate is reduced relative to the growth rate during the ramp so that the etch rate becomes less than the growth rate;removing the first growth gas from the chamber and replacing the first growth gas with a second growth gas capable of providing epitaxial growth at a temperature lower than the high temperature; andreducing the temperature from the high temperature to the temperature lower than the high temperature to allow epitaxial growth to continue at the temperature lower than the high temperature to complete formation of the layer of material.