US 6,143,080 A · Wafer processing reactor having a gas flow control system and method

Abstract

A wafer processing system for delivering a processing gas and an inert gas to a chamber which includes a CVD processing region having a plurality of gas flow paths for conveying the gases to the chamber and exhausting them from the chamber. A flow control system is coupled to each of the exhaust gas flow paths and each of the process gas exhaust flow paths are separately controlled to maintain a constant rate of flow within each of the gas flow paths, independent of the accumulation of deposition byproducts. Utilization of a self-cleaning orifice allows a pressure differential measurement in a process exhaust line to measure flow. The wafer processing system is provided with load and unload regions surrounding the chamber(s), each having additional inert gas exhaust flow paths. A flow characteristic, preferably pressure differential across an orifice, of the gases in each of the regions is measured and a flow control unit is selectively adjusted to maintain a substantially constant exhaust flow rate from each of the regions, in order to compensate for any pressure imbalance across the chamber due to internal (thermal load) or external (environmental) asymmetry that would degrade the performance of an APCVD system.

Claims21

Dependent claims

A chemical vapor deposition processing system for delivering at least one reactant gas and an inert gas to process a wafer or other substrate, comprising:

at least one processing chamber including a processing region formed therein and having at least one gas flow path for conveying said at least one reactant gas into said processing region and another gas flow path for delivering said inert gas to said processing region,
individual exhaust gas flow paths for removing said reactant gas completely within one said path along with some of said inert gas, and another said path for removing only excess inert gas from said processing chamber, and
an exhaust flow control system for separately controlling the flow of gas from each of said exhaust gas flow paths to confine the processing region such that only said reactant and inert gas delivered inside said process chamber is exhausted through said processing region.

A chemical vapor deposition processing system for delivering at least one reactant gas and an inert gas to process a wafer or other substrate, comprising:

at least one process chamber including a processing region formed therein and having at least one inert gas flow path for conveying said at least one reactant gas into said processing region and another gas flow path for delivering said inert gas to said wafer processing system,
at least one exhaust gas flow path for removing said reactant gas and inert gas from said processing chamber, and
an exhaust flow control system for separately controlling the flow of gas from said exhaust gas flow path,
a wafer load and unload region within said processing system at the load and unload sides of said processing region, each having at least one inert gas flow path for delivering inert gas to said load and unload regions,
a load exhaust path and an unload exhaust path internal to said inert gas flow regions,
a first sensor coupled to said load exhaust gas path for measuring a flow characteristic of said gas within said load exhaust gas flow path;
a second sensor coupled to said unload exhaust gas path for measuring a flow characteristic of said gas within said unload gas flow path;
controllers for receiving signals from said first and second sensors;
and
flow control units in each of said load and unload exhaust gas flow paths, said flow control units being selectively adjusted to control the flow rate of the gases in each of said load and unload paths responsive to said controller.

7 more elements

Dependencies are inferred from the claim text.

Wafer processing reactor having a gas flow control system and method

Life of this patent

Wafer processing reactor having a gas flow control system and method

Life of this patent

Abstract

Claims21