Patent ID: 11971217
Assignee: ASM IP HOLDING B.V.
Field: Thermal processes and apparatus (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. A batch furnace assembly for processing wafers, comprising:
a process chamber housing defining a process chamber with a process gas inlet and an exhaust wherein the process chamber housing has a process chamber opening;
a wafer boat housing defining a wafer boat chamber, wherein the process chamber opening connects the process chamber with the wafer boat chamber for transferring wafer boats between the wafer boat chamber and the process chamber;
a door assembly having a closed position in which the door assembly closes off the process chamber opening, wherein the door assembly defines in the closed position a door assembly chamber having a purge gas inlet for supplying purge gas to the door assembly chamber for gas sealingly separating the process chamber from the wafer boat chamber;
a differential pressure sensor assembly fluidly connected to the door assembly chamber and a reference pressure chamber within the wafer boat housing and configured to determine a pressure difference between a pressure in the door assembly chamber and a reference pressure in the reference pressure chamber, the differential pressure assembly comprising a pressure sensor within the door assembly chamber and a pressure sensor within the reference pressure chamber; and
a controller configured to compare the pressure difference with a desired pressure difference based on a pressure difference between the process chamber and the reference pressure chamber to establish whether the pressure difference is in a desired pressure range to confirm that the door assembly effectively closes off the process chamber opening.