Plasma generating units for processing a substrate

• US 10,049,859 B2
• Filed: 07/08/2010
• Issued: 08/14/2018
• Est. Priority Date: 07/08/2009
• Status: Active Grant

• Current Assignee: Aixtron AG
• Original Assignee: Aixtron AG
• Inventors: Savas, Stephen Edward, Galewski, Carl, Wiesnoski, Allan B., Mantripragada, Sai, Joh, Sooyun
• Primary Examiner(s): KENDALL, BENJAMIN R
• Application Number:
  US12/832,947
• Publication Number:
  US 20110005681A1
• Time in Patent Office: 2,959 Days
• Field of Search: 118723 E, 118723 ER, 15634543, 15634545, 15634547
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: C23C 16/26 Deposition of carbon only
• CPC Class Codes: C23C 16/345 Silicon nitride
• CPC Class Codes: C23C 16/40 Oxides
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/407 of zinc, germanium, cadmium, indium, tin, thallium or bismuth
• CPC Class Codes: C23C 16/4412 Details relating to the exhausts, e.g. pumps, filters, scrubbers, particle traps
• CPC Class Codes: C23C 16/45504 Laminar flow
• CPC Class Codes: C23C 16/45519 Inert gas curtains
• CPC Class Codes: C23C 16/45591 Fixed means, e.g. wings, baffles
• CPC Class Codes: C23C 16/466 using thermal contact gas
• CPC Class Codes: C23C 16/50 using electric discharges generation and control of plasma in discharge tubes for surface treatment H01J37/32, H01J37/34
• CPC Class Codes: C23C 16/503 using dc or ac discharges
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: C23C 16/545 for coating elongated substrates
• CPC Class Codes: H01J 37/32036 AC powered
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/32449 Gas control, e.g. control of the gas flow
• CPC Class Codes: H01J 37/32541 Shape
• CPC Class Codes: H01L 21/67069 : for drying etching

Abstract

Apparatus and method for plasma-based processing well suited for deposition, etching, or treatment of semiconductor, conductor or insulating films. Plasma generating units include one or more elongated electrodes on the processing side of a substrate and a neutral electrode proximate the opposite side of the substrate. Gases may be injected proximate a powered electrode which break down electrically and produce activated species that flow toward the substrate area. This gas then flows into an extended process region between powered electrodes and substrate, providing controlled and continuous reactivity with the substrate at high rates with efficient utilization of reactant feedstock. Gases are exhausted via passages between powered electrodes or electrode and divider.

Claims

1. An apparatus for plasma processing of a substrate, the apparatus comprising:

a process chamber housing at least one plasma generating unit (PGU), the PGU having exactly two electrodes, including a first electrode and a second electrode, the first electrode and second electrode being distinct from a substrate support on which the substrate is disposed, wherein each of the first and second electrodes has a length, a width, and a height, with the two electrodes aligned in parallel along their respective length directions, wherein said length is at least four times the width of the respective electrode, and is greater than the height of the respective electrode, wherein the first electrode has a front surface facing and separated by a first gap from the substrate support, wherein the first electrode has a first side surface facing and separated by a second gap from the second electrode, wherein the first electrode has a second side surface opposite the first side surface of the first electrode, wherein each of the minimum distance of the first gap, and the minimum distance of the second gap is greater than 5 mm and less than the width of the first electrode;

said substrate support configured to position the substrate with a first side of the substrate proximate and facing the two electrodes of the PGU, and a second side of the substrate facing the substrate support;

a first gas supply system, comprising a gas source connected to a first reservoir within the PGU, wherein the first reservoir has a plurality of injection holes;

at least one exhaust port, the first gas supply system and the at least one exhaust port configured to cause a first gas to flow at a pressure less than 2,000 Pascals, through the first reservoir and from the injection holes into the second gap between the first side surface of the first electrode and the second electrode and from the second gap into the first gap between the front surface of the first electrode and the substrate support;

a second gas supply system configured to provide a second gas to a second reservoir within at least the first electrode, wherein the second reservoir has a plurality of injection holes configured to introduce the second gas into at least one of the first gap between the front surface of the first electrode and the substrate support and the second gap between the first side surface of the first electrode and second electrode, and wherein the injection holes for the second gas are located closer to the substrate than the injection holes for the first gas; and

a power supply system comprising a first and a second alternating current (AC) power supply, the first AC power supply being distinct from the second AC power supply, the first AC power supply comprising a first powered terminal and a first grounded terminal, the first powered terminal configured to provide a first time-varying electrical potential to at least the first electrode and the second AC power supply comprising a second powered terminal and a second grounded terminal, the second powered terminal configured to provide a second time-varying electrical potential to at least the second electrode so as to sustain a first plasma in the first gap and a second plasma in the second gap.

2. The apparatus of claim 1, wherein the second gas supply system is configured to inject a silicon-containing gas.

3. The apparatus of claim 1, wherein the minimum distance of the first gap between the front surface of the first electrode and the substrate support is less than about 20 mm.

4. The apparatus of claim 1, wherein the minimum distance of the second gap between the first side surface of the first electrode and the second electrode is less than about 20 mm.

5. The apparatus of claim 1, wherein the width of each of the first and second electrodes is at least 1 cm.

6. The apparatus of claim 1, wherein:

the first side surface and the second side surface of the first electrode are each substantially perpendicular to the front surface of the first electrode; and

the second electrode has an opposing side surface that is substantially parallel to the first side surface of the first electrode.

7. The apparatus of claim 1, further comprising an impedance element configured to provide an impedance of the support to electrical ground of less than about 10 Ohms.

8. The apparatus of claim 1, wherein the first side surface and the second side surface of the first electrode are substantially perpendicular to the first side of the substrate.

9. The apparatus of claim 1 wherein edges of the front surface of the first electrode are rounded with a curvature radius of more than about 1 mm.

10. The apparatus of claim 1, wherein the first gas supply system is configured to inject a nitrogen-containing gas.

11. The apparatus of claim 1, wherein the at least one exhaust port is configured to exhaust gas away from the substrate along the second side surface of the first electrode.

12. The apparatus of claim 1, wherein the power supply system is configured to provide power selected from the group consisting of radio frequency (RF), very high frequency (VHF) and ultra high frequency (UHF) power.

13. The apparatus of claim 1, wherein the current supplied from the first AC power supply has a magnitude and a phase.

14. The apparatus of claim 1, wherein the at least one PGU further comprises a divider.

15. The apparatus of claim 1, further comprising a grounded element, wherein the grounded element is separated from the second side surface of the first electrode by a third gap, and wherein the third gap is less than the width of the first electrode.

16. The apparatus of claim 1, wherein the substrate support is configured to position the substrate with a dimension of the substrate parallel to the length of the first and second electrodes.

17. The apparatus of claim 1, wherein the power supply system comprises an adjustable parameter configured to tune a power density of the first plasma relative to a power density of the second plasma.

18. The apparatus of claim 1, wherein a total number of AC power supplies that supply power to a first one of the at least one PGU is equal to a total number of electrodes of the first PGU.

19. An apparatus for plasma processing of a substrate, the apparatus comprising:

a process chamber housing at least one plasma generating unit (PGU) including at least a first electrode and a second electrode, wherein each of the first and second electrodes has a length, a width, and a height, wherein said length is at least four times the width of the respective electrode, and is greater than the height of the respective electrode, wherein the first electrode has a front surface facing and separated by a first gap from a substrate support, wherein the first electrode has a first side surface facing and separated by a second gap from the second electrode, wherein the first electrode has a second side surface opposite the first side surface of the first electrode, wherein each of the minimum distance of the first gap, and the minimum distance of the second gap is greater than 5 mm and less than the width of the first electrode;

the substrate support configured to position the substrate with a first side of the substrate proximate and facing the first and second electrodes of the PGU;

at least a first gas supply system with injection holes;

at least one exhaust port, the first gas supply system and the at least one exhaust port configured to cause a first gas to flow at a pressure less than 2,000 Pascals in the second gap between the first side surface of the first electrode and the second electrode and in the first gap between the front surface of the first electrode and the substrate;

a second gas supply system configured to provide a second gas to a reservoir within at least the first electrode, wherein the reservoir has injection holes configured to introduce the second gas into the second gap between the first side surface of the first electrode and second electrode, wherein said injection holes for the second gas have a length and a width dimension such that a flow of the second gas from the reservoir is along the length dimension of said injection holes and wherein a width of said injection holes for the second gas is less than a cross-sectional dimension of the reservoir; and

a power supply system comprising a first and a second alternating current (AC) power supply, the first AC power supply being distinct from the second AC power supply, the first AC power supply comprising a first powered terminal and a first grounded terminal, the first powered terminal configured to provide a first time-varying electrical potential to at least the first electrode and the second AC power supply comprising a second powered terminal and a second grounded terminal, the second powered terminal configured to provide a second time-varying electrical potential to at least the second electrode so as to sustain a first plasma in the first gap and a second plasma in the second gap.

20. The apparatus of claim 19, further comprising a third element located adjacent to the first electrode, wherein a third gap is located between the second side surface of the first electrode and the third element, and wherein the first gas flows toward the exhaust port through the third gap.

21. The apparatus of claim 19, wherein the first electrode and the second electrode are aligned such that the first electrode and the second electrode are substantially parallel along their respective lengths.

22. The apparatus of claim 19, wherein the first gas supply system is configured to provide at least one of an oxygen-containing gas and a nitrogen-containing gas.

23. The apparatus of claim 19, wherein the first AC power supply is configured to provide electric power in at least one of the radio frequency (RF) band and the very high frequency (VHF) band.

24. The apparatus of claim 19, wherein the substrate support is configured to position the substrate with a dimension of the substrate parallel to a length of the first electrode.