SUBSTRATE PLASMA PROCESSING APPARATUS AND PLASMA PROCESSING METHOD

• US 20090194508A1
• Filed: 01/30/2009
• Published: 08/06/2009
• Est. Priority Date: 02/01/2008
• Status: Active Grant

• Current Assignee: Kioxia Corporation, Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited, Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: ABE, Jun, HAYASHI, Hisataka, YAMADA, Norikazu, UI, Akio, TAMAOKI, Naoki, KAMINATSUI, Takeshi, OHSE, Takeshi, ICHIKAWA, Takashi, HIMORI, Shinji
• Granted Patent: US 8,821,684 B2
• Time in Patent Office: Days
• US Class Current: 216/67
• 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

Abstract

A substrate plasma processing apparatus includes a substrate holding electrode and a counter electrode which are arranged in a chamber, a high frequency generating device which applies a high frequency of 50 MHZ or higher to the substrate holding electrode, a DC negative pulse generating device which applies a DC negative pulse voltage in a manner of superimposing on the high frequency, and a controller controlling to cause intermittent application of the high frequency and cause intermittent application of the DC negative pulse voltage according to the timing of on or off of the high frequency.

Claims

1. A substrate plasma processing apparatus, comprising:

a chamber capable of maintaining a vacuum therein;

a first electrode to hold a substrate in the chamber, the substrate being processed on a main surface thereof;

a counter electrode arranged to face the first electrode in the chamber;

a first supply unit configured to apply a high frequency power having a predetermined frequency of 50 MHz or higher to the first electrode;

a second supply unit configured to apply a predetermined DC negative pulse voltage in a manner of superimposing on the high frequency power to the first electrode; and

a control unit controlling turning on or off of the first supply unit at a predetermined timing to thereby cause intermittent application of the high frequency power, and controlling turning on or off of the second supply unit according to the timing of turning on or off of the first supply unit to thereby cause intermittent application of the DC negative pulse voltage.

2. The apparatus according to claim 1,

wherein the control unit turns off the second supply unit simultaneously with or before turning off of the first supply unit when turning on or off the first supply unit at the predetermined timing to thereby cause the intermittent application of the high frequency power.

3. The apparatus according to claim 2,

wherein when plasma processing an insulating film or a film having an insulator on a bottom portion, the control unit turns off the second supply unit a preset charge-up alleviation time T_pre before turning off of the first supply unit,

where T_pre≧

Q_max/(ZeBN_iv_b), Q_max is a maximum charge amount per unit area that does not cause damage, Z is ionic valency, v_b is Bohm speed as v_b=(kT_e/M_i)^1/2, T_e is electron temperature, k is Boltzmann'"'"'s constant, M_i is ion mass, B is plasma density ratio of a sheath end portion and a bulk portion, e is elementary electric charge, and N_i is ion density.

4. The apparatus according to claim 1,

wherein the control unit turns on the second supply unit simultaneously with or after turning on of the first supply unit when turning on or off the first supply unit at the predetermined timing to thereby cause the intermittent application of the high frequency power.

5. A substrate plasma processing method using a substrate plasma processing apparatus which includes:

a chamber capable of maintaining a vacuum therein;

a first electrode to hold a substrate in the chamber, the substrate being processed on a main surface thereof;

a counter electrode arranged to face the first electrode in the chamber;

a first supply unit configured to apply a high frequency power having a predetermined frequency of 50 MHz or higher to the first electrode; and

a second supply unit configured to apply a predetermined DC negative pulse voltage in a manner of superimposing on the high frequency power to the first electrode, the method, comprising;

turning on or off the high frequency power from the first supply unit at a predetermined timing to thereby cause intermittent application of the high frequency power; and

turning on or off the second supply unit according to the timing of turning on or of f of the high frequency power to thereby cause intermittent application of the DC negative pulse voltage.

6. The method according to claim 5,

wherein turning off the second supply unit simultaneously with or before turning off of the first supply unit when turning on or off the first supply unit at the predetermined timing to thereby cause the intermittent application of the high frequency power.

7. The method according to claim 5,

wherein turning on the second supply unit simultaneously with or after turning on of the first supply unit when turning on or off the first supply unit at the predetermined timing to thereby cause the intermittent application of the high frequency power.