Dry etching method
AssigneeZaidan Hojin Handotai Kenkyu Shinkokai
InventorJunichi Nishizawa
Life of this patent
Estimating the term…
Abstract
A radio frequency and a static electric field are superposedly applied to a low pressure gas to generate a gaseous plasma and to drive ions of selected polarity in a predetermined direction. The processing chamber is pre-evacuated to a sufficiently high vacuum, and an etching gas is introduced into the chamber to be rendered to a low pressure at which the mean free path of the ions is sufficiently long. The pressure of the etching gas may range from the order of 10.sup.-2 Torr to several Torr for etching silicon, using a silicon oxide as a mask material. This method improves the treating accuracy, especially minimizes the amount of side etch, as compared with the conventional plasma etching, and reduces the surface damage when compared with the known ion beam etching.
Claims37
A dry etching method performed in a processing chamber containing at least one workpiece therein, said method comprising the steps of:
- (1) preliminarily evacuating said processing chamber above a first predetermined degree of vacuum to remove residual gas from said processing chamber;
- (2) generating plasma reaction gas containing component particles not required for the etching and component particles required for the etching;
- (3) directing at least part of said component particles required for the etching to move substantially linearly to collide with said at least one workpiece in one direction;
- continuously evacuating said processing chamber to a second predetermined degree of vacuum lower than said first predetermined degree of vacuum and
- thereby performing at least partially reactive directional etching of said workpiece.
A dry etching method performed in a processing chamber having at least one workpiece contained therein, said method comprising the step of:
- (1) evacuating said processing chamber to a predetermined degree of vacuum to remove residual gas from said processing container;
- (2) introducing a reaction gas into the thus evacuated processing chamber;
- (3) applying a plasma exciting field to said reaction gas to form a plasma reaction gas containing ions required for the etching and also ions not required for the etching;
- (4) applying, concurrently, a directing dc field to said plasma reacting gas for directing at least a portion of said ions required for the etching to enhance the directivity of motion to collide with said workpiece substantially in one direction;
- thereby performing at least partially reactive directional etching of said workpiece.
A method of dry etching at least one workpiece contained in a processing chamber, said method comprising the steps of:
- (1) evacuating said processing chamber to a predetermined degree of vacuum to remove residual gas from said processing container;
- (2) introducing a reaction gas into the thus evacuated processing chamber;
- (3) applying a radio frequency plasma generating field to said reaction gas through an electrode to form a plasma reaction gas containing ions required for etching the workpiece and also ions not required for the etching;
- (4) applying, concurrently with said plasma generating field, a dc electric field for directing at least that portion of the ions required for etching and enhancing the directivity of motion to collide with said workpiece substantially in one direction;
- (5) varying the intensity of said directing dc field in accordance with the progress of the etching;
- and
- thereby at least partially reactively directionally etching said workpiece.
Dependencies are inferred from the claim text.