Sputter coating method

• US 3,968,018 A
• Filed: 07/25/1974
• Issued: 07/06/1976
• Est. Priority Date: 09/29/1969
• Status: Expired due to Term

• Current Assignee: Warner-Lambert Company (Pfizer Inc.)
• Original Assignee: Warner-Lambert Company (Pfizer Inc.)
• Inventors: Cartwright, Cyril A., Lane, George C., Elmslie, Keith W.
• Primary Examiner(s): Vertiz, Oscar R.
• Assistant Examiner(s): Langel, Wayne A.
• Application Number:
  US05/491,717
• Time in Patent Office: 712 Days
• Field of Search: 204/192, 204/298
• US Class Current: 204/192.3
• CPC Class Codes: B26B 21/54 Razor-blades B26B21/4006 takes precedence
• CPC Class Codes: C23C 14/568 Transferring the substrates through a series of coating stations C23C14/562 takes precedence

Abstract

An apparatus and method for sequentially cleaning and coating articles. The apparatus is in the form of a multi-chamber device, with each chamber being partially defined by valve units which permit passage of articles to be coated therethrough. Each chamber has associated therewith means for drawing a vacuum therein, several chambers include means for leaking a minute quantity of an inert but ionizable gas therein, and at least one chamber further includes at least one electrode, which may be placed in electrical communication with the articles so as to establish, in one of several ways, a direct current bias on the article with respect to another point within the chamber. Coating material to be transferred to the article is placed on one electrode, preferably in the form of a flat plate, in those chambers in which coating is to take place, whereas target material is not present in the cleaning or other non-coating chambers. One chamber is provided to serve as an air lock so that articles may be removed from it into the air while the chamber is sealed off from an adjacent chamber so as to prevent atmospheric contamination of coating material or articles to be coated in a coating chamber.

Means are provided for moving articles successively from one chamber to another so that the articles may be introduced into one chamber, cleaned, coated by passage into one or more succeeding chambers, and then removed through a last, vacuum or air lock chamber. Cleaning occurs by reverse sputtering, sputter etching, or glow discharge, and coating occurs by diode sputtering of a target material from a target electrode onto the substrate or article to be coated.

Claims

1. A method of batch cleaning and batch coating one array of articles with a thin coating material while maintaining said one array substantially free from contamination, said method comprising the steps of:

a. disposing said one array within a first evacuable region;

b. establishing a predetermined high vacuum in said first evacuable region;

c. establishing a high electrical potential between said one array and an electrode;

d. introducing a minute quantity of an ionizable inert gas into said first region and thus increasing the pressure therein whereby said one array will have at least portions of the surface thereof cleaned by bombardment with ions of said gas attracted to said surfaces;

e. thereafter reestablishing said predetermined high vacuum in said first region;

f. providing spacial communication between said first region and a second evacuable region having said predetermined high vacuum established therein;

g. moving said one array at said predetermined high vacuum into said second region;

h. then isolating said second region from said first region;

i. establishing a high electrical potential between said one array and a target in said second region having a coating of material to be applied to said one array;

j. introducing a controlled quantity of an inert gas into said second region whereby said inert gas increases the pressure therein and, when ionized in the presence of said high potential, causes transfer of said material from said target to said one array;

k. thereafter reestablishing said predetermined high vacuum in said second region;

l. providing spacial communication between said second region and a third evacuable region having said predetermined high vacuum established therein;

m. moving said one array at said predetermined high vacuum to said third region; and

n. isolating said third region from said second region.

2. The method of claim 1 further comprising the steps of:

o. establishing a high electrical potential between said one array and another target in said third region having another coating of material to be applied to said one array;

p. introducing a controlled quantity of an inert gas into said third region whereby said inert gas increases the pressure therein and, when ionized in the presence of said high potential, causes transfer of said material from said another target to said one array;

q. thereafter reestablishing said predetermined high vacuum in said third region;

r. providing spacial communication between said third region and a fourth evacuable region having said predetermined high vacuum established therein;

s. moving said one array at said predetermined high vacuum to said fourth region; and

t. isolating said fourth region from said third region.

3. The method of claim 2 further comprising the steps of:

u. providing spacial communication between said fourth region and ambient atmosphere;

v. removing said one array from said fourth region;

w. isolating said fourth region from ambient atmosphere; and

x. reestablishing said predetermined high vacuum in said fourth region.

4. The method of claim 1 wherein said articles are razor blades.

5. The method of claim 1 further comprising the steps of:

o. providing spacial communication between said third region and ambient atmosphere;

p. removing said one array from said third region;

q. isolating said fourth region from ambient atmosphere; and

r. reestablishing said predetermined high vacuum in said third region.

6. The method of claim 1 wherein steps (a) through (e) are repeated for another array of articles while steps (h) through (k) are being performed on said one array.

7. A method of batch cleaning and batch coating an array of articles with a thin coating material while maintaining said array substantially free from contamination, said method comprising the steps of disposing said array within a first evacuable region;

establishing a predetermined high vacuum in said first evacuable region;

establishing a high electrical potential between said array and a surrounding surface;

introducing a minute quantity of an ionizable inert gas into said first region and thus increasing the pressure therein whereby said array will have at least portions of the surfaces thereof cleaned by bombardment with ions of said gas attracted to said surface;

thereafter reestablishing said predetermined high vacuum in said first region;

providing spacial communication between said first region and a second evacuable region having said predetermined high vacuum established therein;

moving said array at said predetermined high vacuum into said second region;

then isolating said second region from said first region;

establishing a high electrical potential between said array and a target in said second region having a coating of material to be applied to said array;

introducing a controlled quantity of an inert gas into said second region whereby said inert gas increases the pressure therein and, when ionized in the presence of said high potential, causes transfer of said material from said target to said array;

thereafter reestablishing said predetermined high vacuum in said second region;

providing spacial communication between said second region and a third evacuable region having said predetermined high vacuum established therein;

moving said array at said predetermined high vacuum to said third region; and

isolating said third region from said second region.

8. The method of claim 7 further comprising the steps of establishing a high electrical potential between said array and another target in said third region having another coating of material to be applied to said array;

introducing a controlled quantity of an inert gas into said third region whereby said inert gas increases the pressure therein and, when ionized in the presence of said high potential, causes transfer of said material from said another target to said array;

thereafter reestablishing said predetermined high vacuum in said third region;

providing spacial communication between said third region and a fourth evacuable region having said predetermined high vacuum established therein;

moving said array at said predetermined high vacuum to said fourth region; and

isolating said fourth region from said third region.

9. The method of claim 8 further comprising the steps of providing spacial communication between said fourth region and ambient atmosphere;

removing said array from said fourth region;

isolating said fourth region from ambient atmosphere; and

reestablishing said predetermined high vacuum in said fourth region.

10. The method of claim 7 wherein said articles are razor blades.

11. The method of claim 7 further comprising the steps of providing spacial communication between said third region and ambient atmosphere;

removing said array from said third region;

isolating said third region from ambient atmosphere; and

reestablishing said predetermined high vacuum in said third region.

12. A method of cleaning and coating at least one article comprising, inserting said article into a cleaning chamber, evacuating said cleaning chamber, establishing a high electrical potential between said article and a reference point within said cleaning chamber, introducing a minute quantity of an inert gas into the region between said article and said reference point to clean said article by ionic surface bombardment, transferring said article directly from said cleaning chamber to an evacuated coating chamber while maintaining a high vacuum level in said cleaning chamber, isolating said cleaning chamber from said coating chamber into which said article is transferred, establishing an electrical potential between a target disposed within said coating chamber and said article, leaking small quantities of an inert gas into the region between the article and target to sputter surface material from the target to the article, re-evacuating said coating chambers, moving said article from said re-evacuated coating chamber to at least one adjacent evacuated coating chamber, and establishing and maintaining substantially the same vacuum level in each of said coating chambers while moving said article between said coating chambers when said coating chambers are in spatial communication with each other, and, after completion of the coating process, moving said article directly to a previously evacuated article removal chamber disposed adjacent said adjacent evacuated coating chamber to prevent communication between an outside atmosphere and said adjacent evacuated coating chamber, isolating said adjacent evacuated coating chamber from said removal chamber and removing said article from said removal chamber while said adjacent evacuated coating chamber is isolated therefrom.