Gas distribution system for ceramic showerhead of plasma etch reactor

Patent metadata

Field	Value
Publication number	US-10366865-B2
Application number	US-201615005877-A
Country	US
Kind code	B2
Filing date	Jan 25, 2016
Priority date	May 31, 2011
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

A gas delivery system for a ceramic showerhead includes gas connection blocks and a gas ring, the gas connection blocks mounted on the gas ring such that gas outlets in the blocks deliver process gas to gas inlets in an outer periphery of the showerhead. The gas ring includes a bottom ring with channels therein and a welded cover plate enclosing the channels. The gas ring can include a first channel extending ½ the length of the gas ring, two second channels connected at midpoints thereof to downstream ends of the first channel, and four third channels connected at midpoints thereof to downstream ends of the second channels. the cover plate can include a first section enclosing the first channel, two second sections connected at midpoints thereof to ends of the first section, and third sections connected at midpoints thereof to ends of the second sections. The channels are arranged such that the process gas travels equal distances for a single gas inlet in the gas ring to eight outlets in the cover ring allowing equal gas flow.

First claim

We claim:

1. A gas delivery ring configured to supply process gas to an outer periphery of a showerhead of a plasma processing apparatus wherein a semiconductor substrate supported on a substrate support is subjected to plasma processing, the gas delivery ring comprising:
a gas ring having a single gas inlet, a plurality of channels, and a plurality of gas outlets in fluid communication with the gas inlet via the channels;
the channels including a first channel connected to the gas inlet at a midpoint thereof with downstream ends of the first channel equidistant from the gas inlet and from each other, two second channels connected at midpoints thereof to the downstream ends of the first channel with downstream ends of the second channels equidistant from the downstream ends of the first channel and from each other, and four third channels connected at midpoints thereof to downstream ends of the second channels with downstream ends of the third channels connected to the gas outlets; and
a bottom ring and cover ring, the channels extending into an upper surface of the bottom ring and enclosed by the cover ring,
wherein an upper surface of the gas delivery ring includes mounting surfaces having mounting holes therein configured to receive fasteners of gas connection blocks which attach the gas delivery ring to the outer periphery of the showerhead, and wherein the channels are disposed within the same plane.

2. The gas delivery ring of claim 1 , wherein the gas delivery ring includes free ends equidistant from the midpoint of the first channel.

3. The gas delivery ring of claim 2 , wherein an extension limiter connects the free ends of the gas delivery ring.

4. The gas delivery ring of claim 1 , wherein the gas outlets are in an upper surface of the cover ring.

5. The gas delivery ring of claim 1 , wherein surfaces of the channels are coated with a silicon coating.

6. The gas delivery ring of claim 1 , wherein the channels are rounded at locations where the ends of the first channel are connected to midpoints of the second channels and where the ends of the second channels are connected to the third channels, and downstream ends of the third channels are angled inwardly and include rounded ends.

7. The gas delivery ring of claim 1 , wherein the gas inlet is on an outer periphery of the gas delivery ring and an L-shaped channel extends between the gas inlet and the midpoint of the first channel.

8. The gas delivery ring of claim 1 , wherein the cover ring is welded to the bottom ring, the gas outlets are located on a radius of about 10 to 11 inches from a center of the gas delivery ring, the channels are rectangular in cross section with a width of about 0.1 inch and height of about 0.32 inch, the cover ring has a thickness of about 0.03 inch and is located in a recess in an upper surface of the bottom ring, the recess having a width of about 0.12 inch along opposite sides of the channels.

Assignees

• Lam Res Corp

Inventors

• Kang Michael
• Paterson Alex

Classifications

• H10P50/283

  by chemical means · CPC title

• H10P50/244

  comprising alternated and repeated etching and passivation steps · CPC title

• H10P72/0421

  for drying etching · CPC title

• H10P50/242 Primary

  of Group IV materials · CPC title

• H01J37/32642

  Focus rings · CPC title