Method and apparatus for forming a multiple-element thin film based on ion beam sputtering

• US 5,089,104 A
• Filed: 12/03/1990
• Issued: 02/18/1992
• Est. Priority Date: 12/04/1989
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Asao, Hiroshi, Kanda, Naoya, Matsumoto, Kunio, Ishikawa, Yasushi
• Primary Examiner(s): Nguyen, Nam X.
• Application Number:
  US07/620,611
• Time in Patent Office: 442 Days
• Field of Search: 204/192.11, 204/192.13, 204/192.12, 204/298.03, 204/298.04
• US Class Current: 204/192.11
• CPC Class Codes: C23C 14/46 by ion beam produced by an external ion source
• CPC Class Codes: C23C 14/548 Controlling the composition

Abstract

Ion beams drawn out of a plurality of ion beam sources or neutralized beams derived therefrom are projected to a plurality of targets, and sputtered particles discharged from the targets are directed to a substrate. The composition of sputtered particles is measured in the vicinity to the substrate. The measured coomposition is compared with the predetermined reference value and the composition of sputtered particles is controlled based on the result of measurement. sputtered particles having a controlled composition distribution are deposited on the substrate thereby to form a multiple-element thin film.

Claims

1. A method of forming a multiple-element thin film based on ion beam sputtering comprising:

a step of producing ion beams or neutral beams which are neutralized ion beams with a plurality of ion beam sources;

a step of projecting said ion beams or neutral beams to a plurality of targets for sputtering so that said targets discharge sputtered particles;

a step of projecting said sputterd particles onto a substrate;

a step of measuring a ratio of composition of said sputtered particles, which pass by the surface of said substrate, based on the atomic absorption method;

a step of comparing the measured composition ratio of sputtered particles with a predetermined reference composition ratio of sputtered particles and controlling said ion beam sources so that the measured composition ratio of sputtered particles is adjusted to coincide with the predetermined reference composition ratio; and

a step of depositing the sputtered particles, with the measured composition ratio thereof being adjusted, on said substrate thereby to form a thin film.

2. A method of forming a multiple-element thin film based on ion beam sputtering in which ion beams drawn out of a plurality of ion beams sources or neutral beams that are neutralized ion beams are projected to a plurality of targets for sputtering which are provided in correspondence to said ion beam sources and sputtered particles discharged from said targets are deposited on a substrate so that a multiple-element thin film is formed on said substrate, wherein a ratio of composition of sputtered particles which pass by the surface of said substrate is measured based on the atomic absorption method, the result of measurement is compared with a predetermined reference composition ratio of sputtered particles thereby to detect the deviation of composition ratio, output data is computed based on the result of detection so as to achieve the predetermined reference composition ratio of sputtered particles, and power supplied of said ion beam sources are controlled based on the result of computation so that the acceleration voltage and ion current density of said ion beam sources are adjusted, the ratio of composition of sputtered particles which are deposited on said substrate being monitored directly during the film formation.

3. A method of forming a multiple-element thin film based on ion beam sputtering according to claim 2, wherein said targets are made of at least one of metal, metallic oxide and metallic nitride, further comprising an assistant ion beam source of a beam of at least one of oxygen and nitrogen, and a composite metallic compound thin film formed of at least one of composite metallic oxide and composite metallic nitride is formed on said substrate.

4. A method of forming a multiple-element thin film based on ion beam sputtering according to claim 2, wherein said targets are made of at least a metal or alloy, said ion beam sources are formed of ion beams of a rare gaseous element, and a thin film of at least one of alloy and metallic compound is formed on said substrate.

5. A method of forming a multiple-element thin film based on ion beam sputtering according to claim 2, wherein said targets are made of at least one of metal, metallic oxide and metallic nitride, further comprising an assistant ion beam source of a beam of at least one of oxygen and nitrogen, and a multi-element film wiring structure formed of at least one of metallic oxide or metallic nitride is formed on said substrate.

6. A multiple-element ion beam sputtering apparatus comprising:

a substrate;

a plurality of targets which are used as a source material for forming a thin film on said substrate;

a plurality of ion beams sources or neutral beam sources which are provided in correspondence to said targets and operated by being controlled independently of each other to project beams to said targets so that said targets discharge sputtered particles;

means for projecting said sputtered particles onto said substrate so that a thin film is formed on said substrate;

means for measuring a composition ratio of sputtered particles in the vicinity to the surface of said substrate based on the atomic absorption method;

means for comparing the measured composition ratio of sputtered particles measured by said measuring means with a predetermined reference composition ratio of sputtered particles and controlling said ion beam sources or neutral beam sources based on the result of measurement so that the measured composition ratio of sputtered particles coincides with the predetermined reference composition ratio.

7. A multiple-element thin film forming apparatus based on ion beam sputtering comprising:

a plurality of ion beam sources or neutral beam sources which can be controlled independently;

a plurality of targets which are provided in correspondence to said beam sources and used as evaporation sources of the thin film constituents;

means for projecting said beams to said targets so that sputtered particles discharged from said targets are deposited on a substrate;

means for measuring a concentration of sputtered particles, which are discharged from said targets and directed to said substrate, in correspondence to said substrate on the basis of the atomic absorption method;

means for comparing the result of measurement with a predetermined reference composition ratio of sputtered particles thereby to detect a deviation therebetween and for computing output data based on the result of detection so as to achieve the predetermined reference composition ratio of sputtered particles; and

means for controlling said ion beam sources or neutral beam sources based on the result of computation thereby to adjust an acceleration voltage and current density of the beams so that the measured concentration of sputtered particles is controlled, the measured concentration of sputtered particles which are deposited on said substrate being monitored directly during the film formation.

8. A multiple-element thin film forming apparatus based on ion beam sputtering according to claim 7, further comprising, an assistant ion beam source which projects a beam directly to said substrate.

9. A multiple-element thin film forming apparatus based on ion beam sputtering according to claim 7, wherein the means for measuring the concentration of sputtered particles measures a composition ratio of sputtered particles, the means for comparing compares the measured composition ratio with the predetermined reference composition ratio, and the means for controlling adjusts the acceleration voltage and current density in accordance with the detected deviation therebetween.