Monolithic integrated circuit incorporating an inductive component and process for fabricating such an integrated circuit

• US 6,548,365 B2
• Filed: 06/21/2002
• Issued: 04/15/2003
• Est. Priority Date: 03/23/1999
• Status: Expired due to Fees

• Current Assignee: Sakura Technologies, LLC
• Original Assignee: Memscap SA and Planhead-Silmag PHS SA
• Inventors: Valentin, François, Basteres, Laurent, Karam, Jean-Michel, Mhani, Ahmed
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): SARKAR, ASOK K
• Application Number:
  US10/177,435
• Publication Number:
  US 20020160576A1
• Time in Patent Office: 298 Days
• Field of Search: 257/528, 257/531, 336/12, 336/65, 336/107, 336/138, 336/173, 336/186, 336/223, 336/225, 438/329, 438/381, 438/643, 438/648, 438/653
• US Class Current: 438/381
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 28/10 Inductors
• 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: H01L 2924/3011 Impedance

Abstract

A monolithic integrated circuit (1) incorporating an inductive component (2) and comprising:

a semiconductor substrate layer (2);

a passivation layer (4) covering the substrate layer (2);

metal contact pads (5) connected to the substrate (2) and passing through the passivation layer (4) in order to be flush with the upper face (6) of the passivation layer (4);

which circuit also includes a spiral winding (20) which forms an inductor and lies in a plane parallel to the upper face (6) of the passivation layer (4), said winding (20) consisting of copper turns (21-23, 27, 28) having a thickness of greater than 10 microns, the winding ends forming extensions (12) which extend below the plane of the winding (20) and are connected to the contact pads (5).

Claims

1. A process for fabricating a monolithic integrated circuit incorporating an inductive component, which comprises the following steps in which:

a polyimide layer (9) is deposited on a semiconductor substrate (2) covered with a passivation layer (4) and comprising metal pads (5) connected to the substrate (2) and passing through the passivation layer (4) in order to be flush with the upper face (6) of said layer (4);

a silica layer (16) is deposited on said polyimide layer (9);

apertures (30) are made in the silica layer (16) and the polyimide layer (9), said apertures (30) emerging at the metal pads (5);

a metal growth sublayer (33) is deposited on the assembly;

a layer of photosensitive resin is deposited on the metal growth sublayer (33);

the resin is exposed and the regions intended to form the lower face of the inductive component (20) are removed;

a copper layer intended to form the strip of the inductive component is electrolytically deposited on the visible regions of the metal growth sublayer;

the rest of the photosensitive resin and the rest of the metal growth sublayer are removed.

2. The process as claimed in claim 1, which furthermore includes a step of removing the polyimide layer (9).

3. The process as claimed in claim 1, which furthermore includes a step of passivating the copper strip by depositing a layer (28, 40) of gold or gold-based alloy.

4. The process as claimed in claim 1, which includes a step of depositing a metal forming a barrier layer (31) on the metal pad.

5. The process as claimed in claim 4, which includes a step of depositing a matching layer (32) on the metal barrier layer (31).

6. A process for fabricating a monolithic integrated circuit incorporating an inductive component, which comprises the following steps in which:

a benzocyclobutene layer (9) is deposited on a semiconductor substrate (2) covered with a passivation layer (4) and comprising metal pads (5) connected to the substrate (2) and passing through the passivation layer (4) in order to be flush with the upper face (6) of said layer (4);

apertures (30) are made in the benzocyclobutene layer (9), said apertures (30) emerging at the metal pads (5);

a metal growth sublayer (33) is deposited on the assembly;

a layer of photosensitive resin is deposited on the metal growth sublayer (33);

the resin is exposed and the regions intended to form the lower face of the inductive component (20) are removed;

a copper layer intended to form the strip of the inductive component is electrolytically deposited on the visible regions of the metal growth sublayer;

the rest of the photosensitive resin and the rest of the metal growth sublayer are removed.