Vertical load-lock reduced-pressure type chemical vapor deposition apparatus

Claim 1

A CVD apparatus comprising: a reaction chamber including an evacuation port connected to an evacuation means, a reaction gas inlet port connected to a reaction gas supply, and a heater for heating object wafers within said reaction chamber, an auxiliary chamber vertically connected with said reaction chamber, said auxiliary chamber having an elevator for bringing up a boat, for holding said object wafers, to said reaction chamber and bringing down the boat to said auxiliary chamber, a loading-unloading chamber for gas-tightly and provisionally storing object wafers before being loaded into said auxiliary chamber, after being unloaded from said auxiliary chamber following completion of chemical vapor deposition, and before being taken out to ambient atmosphere, said loading-unloading chamber being connected to said auxiliary chamber with a gate valve and to an inert gas introducing means, said loading-unloading chamber having a loading part in a first end for receiving said object wafers from an ambient atmosphere part and loading said object wafers into said auxiliary chamber, an unloading part in a second end for receiving said object wafers from the auxiliary chamber and discharging said object wafers to another ambient atmosphere part, and a loading/unloading part at a center position between said first and second ends for at one time provisionally storing said object wafers having been transferred from said loading part and to be transferred into said auxiliary chamber, and at another time provisionally storing said object wafers having been transferred from said auxiliary chamber and to be transferred to said unloading part, said loading/unloading part being disposed in front of said auxiliary chamber, with said loading part, said loading/unloading part and said unloading part being disposed on a line which is substantially perpendicular to a line connecting the center of said auxiliary chamber and the center of said loading/unloading part, and slide means for slidingly transferring two cassettes, each for carrying a plurality of wafers, between a loading position consisting of said loading part and said loading/unloading part and an unloading position consisting of said loading/unloading part and said unloading part.