Ion-ion plasma atomic layer etch process and reactor

Patent metadata

Field	Value
Publication number	US-2016276134-A1
Application number	US-201514660531-A
Country	US
Kind code	A1
Filing date	Mar 17, 2015
Priority date	Mar 17, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

A reactor with an overhead electron beam source is capable of generating an ion-ion plasma for performing an atomic layer etch process.

First claim

1 . An electron beam plasma reactor comprising:
(1) an upper plasma chamber comprising:
(a) a side wall,
(b) a top electrode support comprising an electrically insulated electrostatic chuck and thermal control apparatus coupled to said top electrode support,
(c) a top electrode thermally coupled to said top electrode support and having a top electrode surface
(d) an RF source power generator coupled to said top electrode or to said top electrode support or to an interior of said upper chamber, and a D.C chucking voltage source coupled to said electrically insulated electrostatic chuck,
(e) a gas distributor,
(f) a grid filter facing said top electrode surface; and
(2) a lower plasma chamber, said grid filter separating said upper plasma chamber from said lower plasma chamber, said lower plasma chamber comprising:
(a) a vacuum chamber body surrounding a processing region, and
(b) a workpiece support pedestal comprising an electrically insulated electrostatic chuck and thermal control apparatus coupled to said workpiece support pedestal, and having a workpiece support surface facing said grid filter.

2 . The plasma reactor of claim 1 further comprising a bias voltage generator coupled to workpiece support pedestal.

3 . The plasma reactor of claim 1 wherein said top electrode comprises one of silicon, carbon, silicon carbide, silicon oxide, aluminum oxide, yttrium oxide, zirconium oxide.

4 . The plasma reactor of claim 1 wherein said RF source power generator comprises a first RF power generator having a first frequency and a second RF power generator having a second frequency.

5 . The plasma reactor of claim 1 further comprising a folded resonator coupled between said RF source power generator and said top electrode.

6 . The plasma reactor of claim 1 wherein said grid filter comprises first and second grids facing one another, said plasma reactor further comprising an acceleration voltage source connected to one of said first and second grids.

7 . The plasma reactor of claim 1 further comprising a first electromagnet or permanent magnet adjacent one of said upper and lower chambers.

8 . The plasma reactor of claim 1 further comprising:
a window in said side wall;
a coil antenna around said window; and
an RF generator coupled to said coil antenna.

9 . A method of processing a workpiece in an electron beam plasma reactor, said method comprising:
dividing a chamber of said reactor into an upper chamber and a lower chamber by a grid filter, and supporting a workpiece in said lower chamber with a surface of said workpiece facing said grid filter along an axis; supplying a gas into said chamber; coupling RF source power into said upper chamber or to an electrode of said upper chamber or to an electrode support, to generate a plasma including beam electrons in said upper chamber to produce an electron beam having a beam propagation direction corresponding to said axis; allowing flow of at least a portion of said beam electrons from said upper chamber to said lower chamber while preventing flow of at least a portion of non-beam electrons and plasma ions from said upper chamber to said lower chamber; and allowing said electron beam to produce a plasma in said lower chamber.

10 . The method of claim 9 further comprising:
supplying a substantially inert gas into said upper chamber and supplying a molecular process gas into said lower chamber.

11 . The method of claim 9 further comprising coupling a bias voltage to said workpiece.

12 . The method of claim 9 wherein said top electrode comprises one of silicon, carbon, silicon carbide, silicon oxide, aluminum oxide, yttrium oxide, zirconium oxide.

13 . The method of claim 9 wherein said RF source power comprises RF power of a first frequency and a RF power of a second frequency.

14 . The method of claim 9 further comprising providing a magnetic field in said chamber from a first magnet comprising either a permanent magnet or an electromagnet.

15 . The method of claim 9 wherein said generating a plasma further comprises applying RF source power to a coil antenna around a window in a sidewall of upper chamber.

16 . A method of performing atomic layer etching using an electron beam plasma source in a process chamber, said method comprising:
dividing said process chamber into upper and lower chambers by a grid filter, said upper chamber having a ceiling electrode, and placing a workpiece in said lower chamber having a surface layer to be etched; furnishing a molecular process gas to said chamber; (I) performing a passivation process comprising:
(A) performing at least one of: (a) coupling a high power level of VHF power into said upper chamber or to said ceiling electrode, or (b) coupling a high level of inductively coupled power into said upper chamber; and
(B) maintaining a bias voltage on said workpiece at zero or below a threshold for etching said surface layer of said workpiece;
(II) performing an etching process comprising:
(A) coupling to said ceiling electrode a high level of RF power;
(B) maintaining a bias voltage on said workpiece above a threshold for etching said surface layer; and
(III) repeating said passivation and etching processes in alternating succession.

17 . The method of claim 16 wherein said furnishing a molecular process gas to said chamber comprises furnishing said molecular process gas into said lower chamber.

18 . The method of claim 17 further comprising furnishing an inert gas into said upper chamber.

19 . The method of claim 16 wherein said furnishing a molecular process gas to said chamber comprises furnishing said molecular process gas into said upper chamber.

20 . The method of claim 19 further comprising furnishing an inert gas into said upper chamber.

Assignees

• Applied Materials Inc

Inventors

• Collins Kenneth S
• Ramaswamy Kartik
• Carducci James D
• Rauf Shahid
• Dorf Leonid
• Yang Yang

Classifications

• H10P72/0471

  comprising at least one ion or electron beam chamber · CPC title

• H10W72/07511

  Treating the bonding area before connecting, e.g. by applying flux or cleaning · CPC title

• H10W72/01571

  Cleaning, e.g. oxide removal or de-smearing · CPC title

• H01J37/32422

  Arrangement for selecting ions or species in the plasma · CPC title

• H01J37/3255 Primary

  Material · CPC title