Cooled optical window for semiconductor wafer heating

Abstract

Abstract A vapor deposition system is provided which uses electromagnetic radiation for heating of a semiconductor wafer. The source of the electromagnetic radiation is typically a lamp having a color temperature corresponding to a wavelength in the range of 0.3 to 0.9 micrometers, and generally for a particular semiconductor to an energy greater than the energy required to cause transitions from the valence band to the conduction band of the semiconductor material used to construct the wafer and more preferably to a color temperature corresponding to an energy substantially at or above the energy required for direct (vertical) transitions from the valence band to the conduction band, thereby providing very high absorption of the incident radiation and very efficient direct heating of the wafer. No substrate is required for conducting heat to the wafer. The radiation is directed by a reflector through a window forming one side of the deposition chamber and impinges directly on the surface of the wafer. Although the windown is typically chosen to be substantially transparent at the frequencies desired for heating the wafer, some absorption does occur, thereby heating the window as well. To maintain optimum control over the deposition process, the window is typically constructed with two spaced-apart plates and water is pumped therethrough to actively control window temperature.

Inventors

• 👤 Imad Mahawili

Bibliographic Details