PLASMA ETCHING APPARATUS AND PLASMA ETCHING METHOD

• US 20120012556A1
• Filed: 02/26/2009
• Published: 01/19/2012
• Est. Priority Date: 02/27/2008
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Matsumoto, Naoki, Okayama, Nobuyuki, Takai, Kazuto, Ko, Reika
• Granted Patent: US 9,263,298 B2
• Time in Patent Office: Days
• US Class Current: 216/69
• CPC Class Codes: H01J 2237/2001 Maintaining constant desired temperature
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/32137 of silicon-containing layers
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/67248 Temperature monitoring

Abstract

A plasma etching apparatus 11 includes a mounting table that holds a semiconductor substrate W thereon; a first heater 18a that heats a central region of the semiconductor substrate W held on the mounting table 14; a second heater 18b that heats an edge region around the central region of the semiconductor substrate W held on the mounting table 14; a reactant gas supply unit 13 that supplies a reactant gas for a plasma process toward the central region of the semiconductor substrate W held on the mounting table 14; and a control unit 20 that performs a plasma etching process on the semiconductor substrate W while controlling the first heater 18a and the second heater 18b to heat the central region and the edge region of the processing target substrate W held on the mounting table 14 to different temperatures.

Claims

1. A plasma etching apparatus comprising:

a processing chamber that performs therein a plasma process on a processing target substrate;

a mounting table that is provided within the processing chamber and holds the processing target substrate thereon;

a first heater that heats a central region of the processing target substrate held on the mounting table;

a second heater that heats an edge region around the central region of the processing target substrate held on the mounting table;

a reactant gas supply unit that supplies a reactant gas for a plasma process to the central region of the processing target substrate held on the mounting table; and

a control unit that performs a plasma etching process on the processing target substrate while controlling the first heater and the second heater to heat the central region and the edge region of the processing target substrate held on the mounting table to different temperatures.

2. The plasma etching apparatus of claim 1, wherein the control unit controls the first heater and the second heater depending on the reactant gas from the reactant gas supply unit.

3. The plasma etching apparatus of claim 1, wherein the control unit controls the first heater and the second heater so as to set a temperature of the edge region to be higher than a temperature of the central region.

4. The plasma etching apparatus of claim 1, wherein the processing target substrate has a polysilicon layer to be etched, and

the control unit performs a plasma etching process on the polysilicon layer.

5. The plasma etching apparatus of claim 1, wherein the first heater and the second heater are embedded in the mounting table.

6. The plasma etching apparatus of claim 1, wherein the mounting table is of a circular plate shape, and

the second heater is of a ring shape.

7. A plasma etching method for performing a plasma etching process on a processing target substrate, the method comprising:

holding the processing target substrate on a mounting table provided within a processing chamber; and

heating a central region and an edge region around the central region of the processing target substrate held on the mounting table to different temperatures, supplying a reactant gas for a plasma process to the central region of the processing target substrate held on the mounting table, and performing the plasma etching process on the processing target substrate.

8. A plasma processing apparatus comprising:

a processing chamber that performs therein a plasma process on a processing target substrate;

a mounting table that is provided within the processing chamber and holds the processing target substrate thereon;

a first heater that heats a central region of the processing target substrate held on the mounting table;

a second heater that heats an edge region around the central region of the processing target substrate held on the mounting table;

a microwave generator that generates a microwave for plasma excitation;

a dielectric plate that is provided at a position facing the mounting table and introduces the microwave into the processing chamber;

a reactant gas supply unit that supplies a reactant gas for a plasma process to the processing chamber; and

a control unit that performs a plasma etching process on the processing target substrate while controlling the first heater and the second heater to heat the central region and the edge region of the processing target substrate held on the mounting table to different temperatures,

wherein the mounting table includes a focus ring positioned to surround the processing target substrate held on the mounting table,

the reactant gas supply unit includes;

a first reactant gas supply unit that is provided at a central portion of the dielectric plate and supplies the reactant gas in a directly downward direction toward a central region of the processing target substrate held on the mounting table, and

a second reactant gas supply unit that is provided at a position directly above the mounting table but not directly above the processing target substrate held on the mounting table and introduces the reactant gas in a directly downward direction toward the focus ring.

9. The plasma processing apparatus of claim 8, wherein the second reactant gas supply unit is provided in the vicinity of the mounting table.

10. The plasma processing apparatus of claim 8, wherein the second reactant gas supply unit includes a ring-shaped member, and

the ring-shaped member is provided with a supply hole through which the reactant gas is supplied.

11. The plasma processing apparatus of claim 10, wherein the processing target substrate is of a circular plate shape,

the ring-shaped member is of a circular ring shape, and

an inner diameter of the ring-shaped member is larger than an outer diameter of the processing target substrate.

12. The plasma processing apparatus of claim 11, wherein the focus ring is of a circular ring shape, and

the supply hole is provided at a position closer to an inner edge of the focus ring rather than an outer edge of the focus ring.

13. A plasma processing method for performing a plasma process on a processing target substrate, the method comprising:

holding the processing target substrate on a mounting table provided within the processing chamber and having a focus ring positioned to surround the processing target substrate held on the mounting table;

generating a microwave for plasma excitation;

introducing the microwave into the processing chamber through the dielectric plate;

performing a control to heat a central region and an edge region of the processing target substrate held on the mounting table to different temperatures; and

supplying a reactant gas in a directly downward direction from a central portion of the dielectric plate toward the central region of the processing target substrate, and supplying the reactant gas in a directly downward direction toward the focus ring from a position directly above the mounting table but not directly above the processing target substrate held on the mounting table.