Other

Mattson Technology, Inc

Concept Systems Design, Inc.

Joseph H MacLeish

Mahesh K Sanganeria

Robert D Mailho

Enrique Suarez Del Solar

Dean M Dumitrescu

A structure and method for holding a susceptor in a single-wafer RF heated CVD reactor allows the center portion of the susceptor to be heated and prevents susceptor and reactor damage due to overdriving and the susceptor from losing contact with a rotatable rod during thermal expansion. A plug, located on the bottom surface of the susceptor, heated by RF energy subsequently heats the center portion of the susceptor, thereby providing constant temperature gradients across the susceptor. The plug is connected to a rod which is contained in an upper tube and extends into a lower tube. The upper tube is connected to the susceptor via a locking mechanism. An upper spring in the upper tube applies a downward force on the upper tube such that an upward force on the bottom of the susceptor compresses the upper spring, thereby relieving stress on the susceptor and preventing damage due to overdriving. A lower spring is provided within a lower tube connected to the rod such that the lower spring forces the rod upward to keep continual contact with the plug during various times of thermal expansion. The two springs also allow easy removal and assembly of the susceptor and rod structure for cleaning and repair.

Susceptor hold-down mechanism

A CVD reactor includes separate reaction and pressure chambers, where the reaction chamber is contained within and isolates process or reactant gases from the pressure chamber. The reactor also includes a gas injection system which pre-heats and injects diffused process gas(es) into the reaction chamber in a somewhat vertical direction through a bottom surface of the reaction chamber. The gas injection system injects hydrogen or other appropriate gas in a vertical direction through the bottom surface of the reaction chamber. The flow of hydrogen or other appropriate gas is intermediate the flow of the process gas(es) and a surface of the reaction chamber, thereby re-directing the process gas flow parallel to the top surface of a wafer therein. In this manner, the reaction chamber does not require a long entry length for the process gas(es). This flow of hydrogen or other suitable gas also minimizes undesirable deposition on the surface of the reaction chamber.

Gas injection system for CVD reactors

The silicon surface of a wafer is cleaned at room temperature in a separate pre-clean chamber prior to epitaxial deposition. Fluorine atoms generated, for example, from NF.sub.3 gas, enter the pre-clean chamber, contact the silicon surface, and etch away native oxide, contaminated silicon, and other damage incurred from prior wafer processes. The cleaned wafer is then transferred in an oxygen-free environment to a deposition chamber, for epitaxial deposition. By cleaning at reduced temperatures, autodoping, slip, and other stress-related problems are alleviated. By using a separate chamber for cleaning, system throughput is increased when compared to prior systems using conventional cleaning methods.

Method of cleaning wafer substrates

A CVD reactor includes separate reaction and pressure chambers, where the reaction chamber is contained within and isolates process gases from the pressure chamber. In this manner, each of the chambers may be designed specifically for its intended purpose. The pressure chamber is of a bell-jar shaped designed to sustain a low-pressure environment. The reaction chamber is of a parallel-plate shaped designed for optimized process gas flow. The reaction chamber is isolated from the pressure chamber such that process gases present in the reaction chamber are separated from and cannot come into contact with the inner surface of the bell jar. In this manner, process gases do not deposit on the walls of the pressure chamber. In one embodiment, the wafer is heated by induction coils external to the process chamber. In this manner, the heat transferred to the wafer is not dependent upon the thickness of deposition layers formed on the walls of the reaction chamber.

CVD reactor having heated process chamber within isolation chamber

A CVD reactor includes separate reaction and pressure chambers, where the reaction chamber is contained within and isolates reactant gases from the pressure chamber. The reactor also includes a gas injection system which injects process gas(es) into the reaction chamber in a somewhat vertical direction through a bottom surface of the reaction chamber. The gas injection system injects hydrogen or other appropriate gas in a vertical direction through the bottom surface of the reaction chamber. The flow of hydrogen or other appropriate gas is intermediate the flow of the process gas(es) and a surface of the reaction chamber, thereby re-directing the process gas flow parallel to the top surface of a wafer therein. In this manner, the reaction chamber does not require a long entry length for the process gas(es). This flow of hydrogen or other suitable gas also minimizes undesirable deposition on the surface of the reaction chamber.

Growing community of inventors

San Ramon, CA, United States of America

Joseph H MacLeish