Metallized vias with and method of fabrication

• US 6,252,304 B1
• Filed: 12/28/1998
• Issued: 06/26/2001
• Est. Priority Date: 11/10/1997
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Cole, Herbert Stanley Jr., Daum, Wolfgang
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): COLEMAN, WILLIAM D
• Application Number:
  US09/221,967
• Time in Patent Office: 911 Days
• Field of Search: 257/759, 257/760, 257/762, 257/772, 257/748, 257/750, 438/118, 438/622, 438/625, 438/627, 438/629, 438/637
• US Class Current: 257/759
• CPC Class Codes: H01L 21/288 from a liquid, e.g. electrolytic deposition
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76844 Bottomless liners
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 2221/1089 Stacks of seed layers
• CPC Class Codes: H05K 2201/0344 Electroless sublayer, e.g. Ni, Co, Cd or Ag; Transferred electroless sublayer
• CPC Class Codes: H05K 2201/09563 Metal filled via
• CPC Class Codes: H05K 2203/072 Electroless plating, e.g. finish plating or initial plating
• CPC Class Codes: H05K 3/388 by the use of a metallic or inorganic thin film adhesion layer
• CPC Class Codes: H05K 3/4076 by thin-film techniques
• CPC Class Codes: H05K 3/422 characterised by electroless plating method; pretreatment therefor
• CPC Class Codes: H05K 3/423 characterised by electroplating method
• CPC Class Codes: H05K 3/4644 by building the multilayer layer by layer, i.e. build-up multilayer circuits making via holes in the insulating layers H05K3/0011; special circuit boards as base or core whereon the multilayer is built H05K3/4602

Abstract

A method includes applying a first seed layer extending over a horizontal surface and via sidewalls of a dielectric material and exposed underlying contact metallization; removing at least some of the first seed layer from the contact metallization and the horizontal surface while leaving a sufficient amount of the first seed layer on the sidewalls as a catalyst for subsequent application of a third seed layer; sputtering a second seed layer over the contact metallization and the horizontal surface; using an electroless solution to react with the first seed layer and apply the third seed layer over the sidewalls; and electroplating an electroplated layer over the second and third seed layers.

Claims

1. A structure comprising:

contact metallization;

dielectric material having vias having sidewalls and extending through to the contact metallization;

a seed layer extending over and in physical contact with the via sidewalls;

a second seed layer extending over and in physical contact with the contact metallization and extending over a horizontal surface of the dielectric material;

an electroplated layer extending over and in physical contact with the seed layer and the second seed layer.

2. The structure of claim 1 wherein the dielectric material has a thickness ranging from about ten microns to about 150 microns and wherein the via sidewalls have slopes ranging from about seventy degrees to about 110 degrees.

3. The structure of claim 2 wherein the dielectric material has a thickness ranging from about ten microns to about seventy five microns and wherein the via sidewalls have slopes ranging from about eighty five degrees to about 95 degrees.

4. The structure of claim 2 wherein the dielectric material comprises a polyimide, the seed layer comprises tin chloride, the second seed layer comprises titanium coated by copper, and the electroplated layer comprises copper.

5. The structure of claim 2 wherein diameters of the vias range from about 12.5 micrometers to about 25 micrometers.

6. A structure comprising:

contact metallization;

dielectric material having vias having steep sidewalls, the vias extending through to the contact metallization;

a seed layer extending over and in physical contact with the via sidewalls, the seed layer comprising tin chloride or palladium chloride;

a second seed layer extending over and in physical contact with the contact metallization and extending over a horizontal surface of the dielectric material, the second seed layer comprising titanium coated by copper;

an electroplated layer extending over and in physical contact with the seed layer and the second seed layer, the electroplated layer comprising copper.

7. A structure comprising:

contact metallization,

dielectric material having vias having sidewalls and extending through to the contact metallization;

a seed layer extending over and in physical contact with the via sidewalls;

a second seed layer extending over and in physical contact with the contact metallization and extending over a horizontal surface of the dielectric material;

a third seed layer extending over and in physical contact with the second seed layer; and

an electroplated layer extending over and in physical contact with the seed layer and the third seed layer.