Apparatus for thermal treatment of substrates

Abstract

Methods and apparatuses are provided for cooling semiconductor substrates prior to handling. In one embodiment, a substrate and support structure combination is lifted after high temperature processing to a cold wall of a thermal processing chamber, which acts as a heat sink. Conductive heat transfer across a small gap from the substrate to the heat sink speeds wafer cooling prior to handling the wafer (e.g., with a robot). In another embodiment, a separate plate is kept cool within a pocket during processing, and is moved close to the substrate and support after processing. In yet another embodiment, a cooling station between a processing chamber and a storage cassette includes two movable cold plates, which are movable to positions closely spaced on either side of the wafer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 09 / 584,656, filed May 30, 2000, which is a continuation of U.S. patent application Ser. No. 09 / 150,986, filed Sep. 10, 1998 (now U.S. Pat. No. 6,108,937).BACKGROUND OF THE INVENTION [0002] This invention relates to methods and devices for cooling bodies such as semiconductor substrates after they are heated. More particularly, the invention relates to cooling a substrate by heat transfer between the substrate and a heat sink prior to handling the substrate. [0003] Semiconductor wafers or other such substrates are subjected to very high treatment or processing temperatures. For example, in certain chemical vapor deposition (CVD) processes, the temperatures can approach 1,200° C. In a typical cycle, a wafer is transferred from a room temperature cassette by a robotic wafer handler into a processing or reaction chamber, where it is subjected to a high temperature treatm...

AI Technical Summary

Benefits of technology

[0014] Advantageously, the illustrated embodiments facilitate conductively cooling a substrate, thus cooling the substrate significantly faster than by radiation alone. As the cooling methods and mechanisms do not require handling the substrate with a pick-up device, down time (specifically that caused by waiting for substrate to reach a temperature at which it can be safely handled) is significantly reduced. Additionally, the substrate can be cooled before moving it from the support structure within the process chamber, in accordance with certain of the above-noted aspects. Few moving parts are required to adapt the invention to existing reactors designs. The faster cool down process will allow a wafer or other substrate to be picked up from or placed on a susceptor in a shorter time, which enhances wafer throughput and ultimately decreases cost of wafer processing.

Problems solved by technology

For example, in an epitaxial silicon deposition reactor, processing temperatures in the reaction chamber are typically in the range of 1,000-1,200° C., while the maximum temperature that the robotic wafer handler can handle is only about 900° C. Furthermore, at high temperatures, the wafer is more vulnerable to physical damage which can be caused by the wafer handler during transportation.

The time required to cool down the wafer to handling temperatures can be very costly to the integrated circuit manufacturer.

This cool down adds to the total cycle time for each wafer and hence decreases the throughput of the system.

This will increase the cost of wafer processing.

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