Method for producing via holes in polymer dielectrics

• US 4,764,485 A
• Filed: 01/05/1987
• Issued: 08/16/1988
• Est. Priority Date: 01/05/1987
• Status: Expired due to Fees

• Current Assignee: General Electric Company, Gesellschaft Fur Biotechnologische Forschung mbH
• Original Assignee: General Electric Company
• Inventors: Yerman, Alexander J., McMullen, James G., Loughran, James A.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Powlikowski, Beverly A.
• Application Number:
  US07/000,617
• Time in Patent Office: 589 Days
• Field of Search: 156/643, 156/655, 156/656, 156/659.1, 148/DIG. 106, 148/DIG. 91, 148/DIG. 92, 148/DIG. 93, 148/DIG. 94, 219/121 LE, 219/121 LH, 219/121 LG, 29/578, 29/590, 29/591, 430/317
• US Class Current: 438/690
• CPC Class Codes: B23K 2101/34 Coated articles , e.g. plated or painted; Surface treated articles
• CPC Class Codes: B23K 2103/08 Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/12 Copper or alloys thereof
• CPC Class Codes: B23K 2103/172 wherein at least one of the layers is non-metallic
• CPC Class Codes: B23K 2103/26 Alloys of Nickel and Cobalt and Chromium
• CPC Class Codes: B23K 2103/42 Plastics B23K2103/16 takes precedence
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/0006 taking account of the properties of the material involved B23K26/32, B23K26/40 take precedence
• CPC Class Codes: B23K 26/361 for deburring or mechanical trimming B23K26/351 takes precedence
• CPC Class Codes: B26F 1/31 by radiation by laser beam B23K26/00
• CPC Class Codes: B29C 59/14 by plasma treatment plasma tubes per se H01J
• CPC Class Codes: H01L 21/31127 Etching organic layers
• CPC Class Codes: H01L 23/5389 the chips being integrally enclosed by the interconnect and support structures
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 2203/0554 Metal used as mask for etching vias, e.g. by laser ablation
• CPC Class Codes: H05K 2203/107 Using laser light shaping a substrate by laser ablation H05K3/0026
• CPC Class Codes: H05K 3/0038 combined with laser drilling through a metal layer
• CPC Class Codes: H05K 3/0041 by plasma etching
• CPC Class Codes: H05K 3/0055 After-treatment, e.g. cleaning or desmearing of holes
• CPC Class Codes: Y10S 148/091 : Laser beam processing of fets
• CPC Class Codes: Y10S 148/092 : Laser beam processing-diodes or transistor
• CPC Class Codes: Y10S 148/093 : Laser beam treatment in general
• CPC Class Codes: Y10S 148/094 : Laser beam treatment of compound devices
• CPC Class Codes: Y10S 148/106 : Masks, special
• CPC Class Codes: Y10S 438/94 : Laser ablative material removal
• CPC Class Codes: Y10S 438/945 : Special, e.g. metal

Abstract

A method for producing a hole in a polymer film includes the steps of depositing a conductive layer onto the polymer film and irradiating a spot on the layer with a burst of focused laser energy at a level sufficient to form an opening in the film and, subsequently, plasma etching the film so as to form a hole of desired depth in the polymer film underlying the opening in the conductive layer. This method is particularly applicable to the formation of multichip intergrated circuit packages in which a plurality of chips formed in a semiconductor wafer are coated with a polymer film covering the chips and the substrates. The holes are provided for the purpose of interconnecting selected chip contact pads via a deposited conductive layer which overlies the film and fills the holes.

Claims

1. A method for producing via holes in a polymer film without employment of a mask, said method comprising the steps of:

coating said film with a thin conductive layer;

successively irradiating single spots at desired locations on said layer, directly above where said via holes are desired, with a burst of electromagnetic energy, each said burst of energy being focussed on a selected one of said spots at a time and being of a level sufficient to evaporate portions of said layer thereat and thereby create openings in said layer; and

plasma etching said film so as to create said via holes therein directly below said openings.

2. The method of claim 1 wherein said electromagnetic energy is produced by a laser.

3. The method of claim 2 in which said laser is an xenon laser.

4. The method of claim 2 in which said laser operates at a wavelength in the range of approximately 0.48 to 0.54 microns.

5. The method of claim 1 in which said spots are each in the range of approximately 50-500 microns in diameter.

6. The method of claim 1 in which said film is from approximately 5 to approximately 50 microns in thickness.

7. The method of claim 2 in which said laser is operated in a pulsed mode.

8. The method of claim 1 in which said polymer film is selected from the group consisting of polysulfone, XYDAR™

, POLYIMIDE, Polyimide-Siloxane Copolymers, MYLAR™ and

epoxy.

9. The method of claim 1 in which said etching occurs in an oxygen atmosphere.

10. The method of claim 1 in which said etching occurs in an atmosphere comprising approximately 80% oxygen and 20% CF₄.

11. The method of claim 1 in which said etching occurs at a pressure of approximately 0.5 torr.