Plasma processing device with shower plate having protrusion for suppressing film formation in gas holes of shower plate

• US 10,557,200 B2
• Filed: 09/04/2014
• Issued: 02/11/2020
• Est. Priority Date: 09/11/2013
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Ikeda, Taro, Kasai, Shigeru, Hara, Emiko, Fujino, Yutaka, Osada, Yuki, Nakagomi, Jun, Komatsu, Tomohito
• Primary Examiner(s): Kurple, Karl
• Application Number:
  US14/917,414
• Publication Number:
  US 20160222516A1
• Time in Patent Office: 1,986 Days
• CPC Class Codes: B05B 1/005 Nozzles or other outlets specially adapted for discharging one or more gases
• CPC Class Codes: B05B 1/14 with multiple outlet openings B05B1/02, B05B1/26 take precedence; with strainers in or outside the outlet opening
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45574 Nozzles for more than one gas
• CPC Class Codes: C23C 16/511 using microwave discharges
• CPC Class Codes: H01J 2237/332 Coating
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/3222 Antennas
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/02211 the compound being a silane, e.g. disilane, methylsilane or chlorosilane
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD

Abstract

A plasma processing device processes a substrate by generating plasma using a surface wave formed on a surface of a shower plate by a supplied microwave, which includes a plasma generating antenna equipped with the shower plate for supplying first and second gases into a processing vessel, and a drooping member installed to protrude downward from a lower end surface of the shower plate. An outer surface of the drooping member spreads outward as it goes from a top end to a bottom end thereof. The shower plate includes first and second gas supply holes through which the first and second gases are supplied into the processing vessel, respectively. The first gas supply holes are disposed inward of the outer surface of the drooping member. The second gas supply holes are disposed outward of the outer surface of the drooping member.

Claims

1. A plasma processing device that processes a substrate by generating a plasma using a surface wave formed on a surface of a shower plate by a supplied microwave, the plasma processing device including a plasma generating antenna which is provided with the shower plate configured to supply a first gas and a second gas into a processing vessel, the plasma processing device comprising:

a protrusion member made of a conductor and installed on the shower plate to protrude downward from a lower end surface of the shower plate, the protrusion member having a truncated conical shape,

wherein the truncated conical shape of the protrusion member is defined by an upper end surface, a lower end surface and a lateral surface extending between the upper end surface and the lower end surface, a diameter of the lower end surface being larger than a diameter of the upper end surface,

the lateral surface being inclined such that the supplied microwave is reflected from the lateral surface in a lateral direction and an upwardly inclined direction and the lateral surface having a parabolic shape spreading outward from the upper end surface to the lower end surface, wherein the shower plate includes a plurality of first gas supply holes through which the first gas is supplied into the processing vessel and a plurality of second gas supply holes through which the second gas is supplied into the processing vessel, wherein the upper end surface of the protrusion member is in contact with a lower end surface of the shower plate;

through-holes extending from the upper end surface of the protrusion member to the lower end surface of the protrusion member are formed in the protrusion member; and

the first gas supply holes are connected to the through-holes, wherein the second gas supply holes are disposed on the lower end surface of the shower plate to surround a portion of the lower end surface of the shower plate being in contact with the upper end surface of the protrusion member, and wherein the through-holes of the protrusion member are formed at positions corresponding to minimum values of an electric field intensity distribution on a circumference of a circle having a predetermined radius in the lower end surface of the protrusion member, which are obtained by a Bessel function as solutions of a Bessel equation for the minimum values of the electric field intensity distribution.

2. The plasma processing device of claim 1, wherein the protrusion member is formed in an annular shape, and

wherein the first gas supply holes are disposed inward of an inner surface of the protrusion member.

3. The plasma processing device of claim 2, wherein a plurality of supply nozzles configured to protrude vertically downward from a bottom surface of the shower plate is connected to the first gas supply holes, respectively.

4. The plasma processing device of claim 1, wherein the first gas is a gas that is more easily decomposed than the second gas.

5. The plasma processing device of claim 4, wherein the first gas is a raw material gas and the second gas is a plasma generation gas.

6. The plasma processing device of claim 1, wherein a microwave radiation hole through which the microwave is radiated into the processing vessel is formed in the shower plate, and

wherein the microwave radiation hole is disposed inward of an outer circumferential end portion of the protrusion member as viewed from the top.