Apparatus of metal-organic chemical vapor deposition being automatically controlled gas flow rate of vent line

摘要

minimize the consumption that vent flow and accurately adjust the vent flow rate and a change in the recipe according to the flow rate of the vent gas in vent line can be appropriately changed by the flow rate will be automatically presented for metal-organic chemical vapor deposition apparatus to control. The apparatus of give to determine the pressure of the reaction chamber, through the reaction chamber and to a pressure change in the vent line of the vent line and the first vent flow rate to control the first vent flow to the main line and the pressure difference is not 0 As expression of the automatic control valve includes an automatic control. At this time, a pressure change in the vent line is y (dx) = a * dx + b, where, y is the pressure change in the vent line, a is [(P (v) _max - P ( v) _min ] / [P (r) _max - P (r) _min ] is, dx is changed smile chamber pressure responses and , b is the minimum value of the vent line pressure. In addition, P (v) _max is the maximum vent line pressure in the recipe for a given epitaxial layer, P (v) _min is at least the vent line pressure, P (r) _max is the maximum reaction chamber pressure under the same conditions and, P (r) _min is the pressure chamber at least reaction. ;