SUBSTRATE PROCESSING APPARATUS AND SUBSTRATE PROCESSING METHOD

• US 20100072172A1
• Filed: 09/18/2009
• Published: 03/25/2010
• Est. Priority Date: 09/24/2008
• Status: Abandoned Application

• Current Assignee: Tokyo Electron Limited, Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Tokyo Electron Limited, Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Abe, Jun, Ohse, Takeshi, Yamada, Norikazu, Kaminatsui, Takeshi, Himori, Shinji, Ui, Akio, Hayashi, Hisataka
• Application Number:
  US12/562,137
• Publication Number:
  US 20100072172A1
• Time in Patent Office: Days
• US Class Current: 216/67
• CPC Class Codes: H01J 2237/3341 Reactive etching
• CPC Class Codes: H01J 37/32009 Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources plasma generation in general H05H1/24
• CPC Class Codes: H01J 37/32027 DC powered
• CPC Class Codes: H01J 37/32045 Circuits specially adapted for controlling the glow discharge
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32137 controlling of the discharge by modulation of energy
• CPC Class Codes: H01J 37/32532 Electrodes
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/31138 by dry-etching
• CPC Class Codes: H01L 21/32136 using plasmas
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 22/14 for electrical parameters, e.g. resistance, deep-levels, CV, diffusions by electrical means
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32

Abstract

There are provided a substrate processing apparatus and a substrate processing method realizing an effective reduction of a voltage change of a substrate on an electrode to reduce the variation of incident energy of ions entering the substrate. The substrate processing apparatus includes: a first electrode holding a substrate on a main surface of the first electrode; a second electrode facing the first electrode; a RF power source applying to the first electrode a RF voltage whose frequency is equal to or higher than 40 MHz; and a pulse voltage applying unit applying to the first electrode a pulse voltage decreasing in accordance with a lapse of time, by superimposing the pulse voltage on the RF voltage.

Claims

1. A substrate processing apparatus, comprising:

a chamber;

a first electrode disposed in the chamber and holding a substrate on a main surface of the first electrode;

a second electrode disposed in the chamber to face the first electrode;

a RF power source applying to the first electrode a RF voltage whose frequency is equal to or higher than 40 MHz; and

a pulse voltage applying unit applying to the first electrode a pulse voltage decreasing in accordance with a lapse of time, by superimposing the pulse voltage on the RF voltage.

2. The substrate processing apparatus according to claim 1,

wherein the pulse voltage applying unit comprises:

a power source outputting a voltage periodically decreasing in accordance with the lapse of time; and

a first switching unit applying the voltage output from the power source, to the first electrode at a predetermined time interval.

3. The substrate processing apparatus according to claim 1,

wherein the pulse voltage applying unit comprises:

a plurality of power sources outputting voltages different from each other; and

a second switching unit selecting a voltage among the voltages output from the power sources at a predetermined time interval to apply the selected voltage to the first electrode.

4. The substrate processing apparatus according to claim 3, further comprising:

a voltage measuring unit measuring a voltage of the first electrode or a plasma measuring unit measuring a state of plasma; and

a switching instruction unit instructing the second switching unit to switch among the voltages output from the power sources, according to a result of the measurement by the voltage measuring unit or the plasma measuring unit.

5. The substrate processing apparatus according to claim 4,

wherein the state of the plasma is electron density or electron temperature of the plasma.

11. The substrate processing apparatus according to claim 1,

wherein a voltage change of the substrate held on the first electrode in one pulse or in one pulse group is 50 volts or less.

6. A substrate processing apparatus, comprising:

a chamber;

a first electrode disposed in the chamber and holding a substrate on a main surface of the first electrode;

a second electrode disposed in the chamber to face the first electrode;

a RF power source applying to the first electrode a RF voltage whose frequency is equal to or higher than 40 MHz;

a pulse voltage applying unit applying a pulse voltage to the first electrode by superimposing the pulse voltage on the RF voltage;

a variable capacitance capacitor interposed between the first electrode and the pulse voltage applying unit and connected in series to the first electrode;

a voltage measuring unit measuring a voltage of the first electrode or a plasma measuring unit measuring electron density of plasma; and

a control unit changing electric charge capacitance of the variable capacitance capacitor according to a result of the measurement by the voltage measuring unit or the plasma measuring unit.

7. A substrate processing apparatus, comprising:

a chamber;

a first electrode disposed in the chamber and holding a substrate on a main surface of the first electrode;

a second electrode disposed in the chamber to face the first electrode;

a RF power source applying to the first electrode a RF voltage whose frequency is equal to or higher than 40 MHz; and

a pulse voltage applying unit applying to the first electrode a voltage having a waveform in which a first period and a second period are repeated, by superimposing the voltage on the RF voltage, the first period having a pulse group waveform including N1 pieces of pulsed waveforms which are repeated with a break time t1 and a frequency ω

1, and the second period being a break time t2 not including a pulsed waveform and longer than the break time t1.

8. The substrate processing apparatus according to claim 7, further comprising:

a voltage measuring unit measuring a voltage of the first electrode or a plasma measuring unit measuring electron density of plasma; and

a control unit controlling at least one of the number N1,

the frequency ω

1, and the break times t1, t2 according to a result of the measurement by the voltage measuring unit or the plasma measuring unit.

9. The substrate processing apparatus according to claim 7,

wherein the break time t1 is given by the following expression:

t1<

1/ω

p [second],

where

ω

p (=e²N₀/(ε

₀mi))^1/2;

plasma ion frequency, where

e;

electron elementary quantum

ε

₀;

vacuum permittivity

mi;

mass of ions

N₀;

plasma density

10. A substrate processing apparatus, comprising:

a chamber;

a first electrode disposed in the chamber and holding a substrate on a main surface of the first electrode;

a second electrode disposed in the chamber to face the first electrode;

a RF power source applying to the first electrode a RF voltage whose frequency is equal to or higher than 40 MHz;

a pulse voltage applying unit applying a pulse voltage to the first electrode by superimposing the pulse voltage on the RF voltage;

a variable resistor provided between the pulse voltage applying unit and the first electrode; and

a control unit controlling a resistance value R of the variable resistor.

12. A substrate processing method, comprising:

holding a substrate to be processed on an electrode disposed in a chamber;

applying to the electrode a RF voltage whose frequency is equal to or higher than 40 MHz; and

applying to the electrode a pulse voltage decreasing in accordance with a lapse of time, by superimposing the pulse voltage on the RF voltage.

13. A substrate processing method, comprising:

holding a substrate to be processed on an electrode disposed in a chamber;

applying to the electrode a RF voltage whose frequency is 40 MHz or higher; and

applying to the electrode a voltage having a waveform in which a first period and a second period are repeated, by superimposing the voltage on the RF voltage, the first period having a pulse group waveform including N1 pieces of pulsed waveforms which are repeated with a break time t1 and a frequency ω

1, and the second period being a break time 2 not including a pulsed waveform and longer than the break time t1.