System for improved pressure control in horizontal diffusion furnace scavenger system for controlling oxide growth
View Patent ↗The present invention relates generally to semiconductor wafer fabrication and more particularly but not exclusively to advanced process control methodologies for controlling oxide formation using pressure. The present invention, in one or more implementations, includes a pressure stabilization system to dynamically adjust scavenger pressure in a furnace during wafer fabrication in relation to a pressure formation range, value, or one or more pressure indicators in a wafer fabrication process.
1. A pressure stabilizing system for wafer fabrication processing, the system comprising:
a wafer loading system for loading one or more unprocessed wafers into a horizontal diffusion furnace for processing having a loader for loading and unloading, wherein the wafer loading system includes a boat loader integrated with a paddle and sealing door, wherein the sealing door forms a sealing gap between the sealing door and a first area of the horizontal diffusion furnace,
the horizontal diffusion furnace capable of operation for a predetermined recipe with the wafer loading system, a gas cabinet and a power system to process the one or more unprocessed wafers,
a pressure stability control system having a pressure sensor in a first area of the furnace in communication with a loading controller capable of adjustably positioning a loader of the wafer loading system to a predetermined horizontal location in relation to a comparison of a measured pressure in the first area and a predetermined formation pressure range, wherein the first area is a scavenger area in the furnace, and
an exhaust release system capable of releasing exhaust gas from the furnace.
2. The system of claim 1 , wherein the sealing gap is approximately less than 2 centimeters in width.
3. The system of claim 1 , wherein the predetermined horizontal location is of a distance of less than one centimeter from an original horizontal location.
4. The system of claim 3 , wherein after positioning the wafer loading assembly to the predetermined horizontal location, the exhaust pressure is less than atmospheric pressure and is also less than scavenger pressure.