Ion implantation apparatus, ion implantation method and semiconductor device

• US 6,140,656 A
• Filed: 11/06/1995
• Issued: 10/31/2000
• Est. Priority Date: 01/10/1995
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Fujii, Atsuhiro
• Primary Examiner(s): BERMAN, JACK I
• Application Number:
  US08/554,015
• Time in Patent Office: 1,821 Days
• Field of Search: 250/492.21, 250/423 P, 204/157.22
• US Class Current: 250/492.21
• CPC Class Codes: H01J 2237/0815 Methods of ionisation
• CPC Class Codes: H01J 2237/31705 Impurity or contaminant control
• CPC Class Codes: H01J 27/24 using photo-ionisation, e.g. using laser beam
• CPC Class Codes: H01J 37/08 Ion sources; Ion guns

Abstract

An ion generator vessel can be filled up with raw material gas containing a specific gas component. The ion generator vessel can be irradiated with a laser beam from a laser oscillator. Due to the beam which is applied into the ion generator vessel, only the specific gas component is selectively excited by multi-photon absorption, to generate ions. Thus, a semiconductor substrate can be inhibited from damage in ion implantation, and processability such as the throughput etc. can be improved.

Claims

1. An ion implantation apparatus for ionizing gas and implanting ions as formed into a wafer being placed in said apparatus, said ion implantation apparatus comprising:

an ion generator vessel capable of being filled up with raw material gas containing specific gas; and

light generation means being so arranged as to generate light having a single wavelength being substantially identical to an absorption wavelength of said specific gas for applying said light into said ion generator vessel,

only specific gas consisting of chemical material with a necessary mass number being selectively excited and ionized by causing one atom or one molecule of said specific gas to absorb only one photon using light being applied into said ion generator vessel.

2. The apparatus according to claim 1, wherein:

the raw material gas is BF₃ ; and

the ions to be implanted into the wafer are ¹⁰ B ions.

3. An ion implantation method of ionizing gas and implanting ions as formed into a wafer being placed in an apparatus, said method comprising the steps of:

filling an ion generator vessel with raw material gas containing specific gas;

generating light having a single wavelength being substantially identical to an absorption wavelength of said specific gas by light generation means;

applying said light into said ion generator vessel and causing one atom or one molecule of said specific gas to absorb only one photon for selectively exciting and ionizing only specific gas consisting of chemical material with a necessary mass number; and

implanting said ions into said wafer.

4. The method according to claim 3, wherein:

the raw material gas is BF₃ ; and

the ions to be implanted into the wafer are ¹⁰ B ions.