Substrate processing apparatus and substrate processing method

• US 10,388,544 B2
• Filed: 02/19/2015
• Issued: 08/20/2019
• Est. Priority Date: 09/24/2008
• Status: Active Grant

• Current Assignee: Kioxia Corporation, Tokyo Electron Limited
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ui, Akio, Hayashi, Hisataka, Kaminatsui, Takeshi, Himori, Shinji, Yamada, Norikazu, Ohse, Takeshi, Abe, Jun
• Primary Examiner(s): Dhingra, Rakesh K
• Application Number:
  US14/626,277
• Publication Number:
  US 20150162223A1
• Time in Patent Office: 1,643 Days
• Field of Search: 118723 E, 118723 ER, 15634543-34547
• 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;

an inlet configured to introduce a gas for etching into the chamber;

a first electrode disposed in the chamber and having a main surface for placing a substrate thereon;

a second electrode disposed in the chamber and facing the first electrode;

a radio frequency (RF) power source configured to apply a RF voltage to the first electrode to generate ions of the gas, the RF voltage having a frequency of 40 MHz or higher; and

a voltage pulse generator configured to superimpose a voltage waveform on the RF voltage applied to the first electrode to lead the ions onto the substrate for its etching,

the voltage waveform having a first period and a second period alternately repeated,

the first period including N1 negative voltage pulses with a frequency of ω

1 and break times t1 of 0.2 μ

sec or less between the voltage pulses,

the second period being a break time t2 lacking a voltage pulse, the break time t2 being longer than each break time t1, and

the voltage waveform having a voltage level of zero in the break times t1 and t2.

2. The apparatus according to claim 1, further comprising:

a voltage monitor configured to measure a voltage of the first electrode; and

a controller configured to control at least one of the number N1, the frequency co1, and the break times t1, t2 in correspondence with the measured voltage.

3. The apparatus according to claim 1, further comprising:

a plasma monitor configured to measure an electron density of plasma; and

a controller configured to control at least one of the number N1, the frequency co1, and the break times t1, t2 in correspondence with the measured electron density.

4. The apparatus according to claim 1, wherein the break time t1 is determined based on the 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.