Enhanced inductively coupled plasma reactor

• US 6,022,460 A
• Filed: 03/22/1999
• Issued: 02/08/2000
• Est. Priority Date: 01/18/1999
• Status: Expired due to Term

• Current Assignee: Jungseok-Inha School's Foundation
• Original Assignee: Jungseok-Inha School's Foundation
• Inventors: Jeong, Jae Seong, Kim, Chul ho, O, Beam-Hoan, Park, Se-Geun
• Primary Examiner(s): DIAMOND, ALAN D
• Application Number:
  US09/273,996
• Time in Patent Office: 323 Days
• Field of Search: 204/298.06, 204/298.08, 204/298.34, 204/298.16, 156/345, 118/723 IR, 118/723 I, 427/569, 216/67, 216/68, 216/70
• US Class Current: 204/298.06
• CPC Class Codes: C23C 16/507 using external electrodes, e.g. in tunnel type reactors
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/3266 Magnetic control means

Abstract

An enhanced inductively coupled plasma reactor which comprises; a chamber; a power supply for providing radio-frequencies necessary to generate plasma within the chamber; an antenna for producing electric fields and magnetic fields with a radio-frequency power from the power supply to generate plasma within the chamber; Helmholtz coils for shaking the plasma with intermittent modulation of a weak magnetic field to increase the density of the plasma and decrease the electron temperature and enhance the uniformity of the plasma, the Helmholtz coils consisting of two coils which are symmetrically arranged with a common axis, winding around the chamber at an upper position and a lower position, respectively, the weak magnetic field being produced by providing a combination of a direct current and an alternating current to the Helmholtz coils; a wafer stage and support; a bias RF power supply for controlling ion energies, connected to the wafer stage; and a matching box for optimally controlling and transferring the power from the bias RF power supply. Axis-directed magnetic fields which vary with time are formed by the provision of the combination of the currents. When they are controlled in various cycles, the plasma can be effectively shaken and a resonant effect occurs, thereby increasing the ion density and decreasing the electron temperature.

Claims

1. An enhanced inductively coupled plasma reactor, comprising:

a chamber for providing a space in which plasma generated is maintained and plasma reaction processes are carried out;

a power supply for providing radio-frequencies necessary to generate plasma within the chamber;

an antenna for producing electric fields and magnetic fields with a radio-frequency power from the power supply to generate plasma within the chamber, said antenna being in any form;

Helmholtz coils for shaking the plasma with intermittent modulation of a weak magnetic field to increase the density of the plasma and enhance the uniformity of the plasma, said Helmholtz coils consisting of two coils which are symmetrically arranged with a common axis, winding around the chamber at an upper position and a lower position, respectively, said weak magnetic field being produced by providing a combination of a direct current and an alternating current to said Helmholtz coils;

a wafer stage and support for supporting a target which is treated by the plasma reaction processes and maintaining the temperature of the wafer;

a bias RF power supply for controlling ion energies, connected to the wafer stage; and

a matching box for optimally controlling and transferring the power from the bias RF power supply.

2. An enhanced inductively coupled plasma reactor as set forth in claim 1, further comprising:

a coil power supply for providing low-frequency powers to the Helmholtz coils; and

a power controller for periodically controlling the power provision of said coil power supply.

3. An enhanced inductively coupled plasma reactor as set forth in claim 2, wherein said Helmholtz coils are provided with a low frequency less than 100 Hz.

4. An enhanced inductively coupled plasma reactor as set forth in claim 1, wherein said plasma is modified in its condition by changing the radii of the coils and the distance therebetween on the basis of the Helmholtz coil definition in which the radii of the two coils is equal to the distance therebetween.

5. An enhanced inductively coupled plasma reactor as set forth in claim 4, wherein any one of said two coils is provided with a direct current while the other is provided with an alternating current.