Showerhead assembly with metrology port purge

Abstract

A method and apparatus that may be utilized for chemical vapor deposition and / or hydride vapor phase epitaxial (HVPE) deposition are provided. In one embodiment, the apparatus is a processing chamber that includes a showerhead with separate inlets and channels for delivering separate processing gases into a processing volume of the chamber without mixing the gases prior to entering the processing volume. In one embodiment, the showerhead includes metrology ports with purge gas assemblies configured and positioned to deliver a purge gas to prevent deposition thereon. In one embodiment, the metrology port is configured to receive a temperature measurement device, and the purge gas assembly is a concentric tube configuration configured to prevent deposition on components of the temperature measurement device. In one embodiment, the metrology port has a sensor window and is configured to receive an optical measurement device, and the purge gas assembly and sensor window are configured to prevent deposition on the sensor window.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionEmbodiments of the present invention generally relate to methods and apparatus for chemical vapor deposition (CVD) on a substrate, and, in particular, to a showerhead design for use in metal organic chemical vapor deposition (MOCVD) and / or hydride vapor phase epitaxy (HVPE).2. Description of the Related ArtGroup III-V films are finding greater importance in the development and fabrication of a variety of semiconductor devices, such as short wavelength light emitting diodes (LEDs), laser diodes (LDs), and electronic devices including high power, high frequency, high temperature transistors and integrated circuits. For example, short wavelength (e.g., blue / green to ultraviolet) LEDs are fabricated using the Group III-nitride semiconducting material gallium nitride (GaN). It has been observed that short wavelength LEDs fabricated using GaN can provide significantly greater efficiencies and longer operating lifetimes than short wavelen...

AI Technical Summary

Benefits of technology

One embodiment of the present invention provides a showerhead assembly comprising a showerhead having a first metrology port defining an interior region and extending through the showerhead and a second metrology port extending through the showerhead. The showerhead assembly further comprises a first metrology assembly having an optical element that is at least partially disposed within the interior region of the first metrology port, a first purge gas assembly having a first gas inlet coupled to a purge gas source and configured to direct a purge gas through the interior region of the first metrology port to prevent deposition of material on the optical element, a second metrology assembly having a sensor window disposed adjacent the second metrology port, and a second purge gas assembly having a gas inlet coupled to the purge gas source and configured to direct the purge gas toward the sensor window to prevent deposition of material thereon.

Another embodiment provides a showerhead assembly comprising a showerhead having a metrology port defining an interior region and extending through the showerhead, a metrology assembly having an optical element that is at least partially disposed within the interior region of the metrology port, and a purge gas assembly having a first gas inlet coupled to a purge gas source and configured to direct a purge gas toward the optical element to prevent deposition of material thereon, wherein a sheath is concentrically disposed about the optical element and within the interior region, and wherein the sheath has an aperture in fluid communication with the first gas inlet.

Problems solved by technology

Interaction of the precursor gases with the hot hardware components, which are often found in the processing zone of an LED or LD forming reactor, generally causes the precursor to break-down and deposit on these hot surfaces.

The deposition of the precursor materials on the hot surfaces can be especially problematic when it occurs in or on the precursor distribution components, such as the showerhead.

Additionally, deposition on metrology ports disposed in the precursor distribution components affects the accurate measurement and control of conditions within the processing zone of the reactor.

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