United States Patent   Patent Number: 5,133,826
Dandl  Date of Patent: Jul. 28, 1992
 ELECTRON CYCLOTRON RESONANCE PLASMA SOURCE
 Inventor: Raphael A. Dandl, San Marcos, Calif.
 Assignee: Applied Microwave Plasma Concepts, Inc., Carlsbad, Calif.
 Appl. No.: 320,947
 Filed: Mar. 9,1989
 Int. CI.' H01L 21/00
 U.S. CI 156/345; 156/643;
 Field of Search 156/345, 643; 427/47;
 References Cited
U.S. PATENT DOCUMENTS
4,745,337 5/1988 Pichot et al 204/298.37 X
4,776,918 10/1988 Otsubo et al 118/728
4,778,561 10/1988 Ghanbari 156/345
4,844,767 7/1989 Okudaira et al 156/345
Primary Examiner—Richard Bueker
Assistant Examiner—Thi Dang
Attorney. Agent, or Firm—Robert C. Hill; John A.
A method and apparatus are disclosed employing elec
tron cyclotron resonant (ECR) heating to produce plasma for applications including but not limited to chemical vapor deposition and etching. A magnetic field is formed by magnets circumferentially arranged about a cylindrical and symmetrical chamber with microwave power injected perpendicularly to a longitudinal axis of the chamber for preventing line-of-sight communication of resulting energetic electrons through an outlet at one axial end of the chamber. The circumferential magnets in the symmetrical chamber cause precessing of the electrons resulting in greatly increased plasma density and ion flux or current density even at low gas pressures which are preferably maintained for establishing unidirectionality or anisotropic plasma characteristics. A magnetic field free region is formed between the plasma forming region containing the microwave power source and the circumferential magnets in order to also produce uniformity of plasma distribution in a plasma stream approaching the outlet. Thus, with specimens aranged in communication with the outlet, the above characteristics are maintained for the plasma stream over substantial transverse dimensions larger than the specimen.