Integrated switching voltage regulator using copper process technology

• US 7,268,410 B1
• Filed: 01/24/2005
• Issued: 09/11/2007
• Est. Priority Date: 01/24/2005
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Johnson, Peter, Hopper, Peter J., Hwang, Kyuwoon, Drury, Robert
• Primary Examiner(s): Weiss; Howard
• Assistant Examiner(s): Ingham; John C
• Application Number:
  US11/041,658
• Time in Patent Office: 960 Days
• Field of Search: 257/19, 257/548, 257/379, 257/516, 257/531, 257/E27.009
• US Class Current: 257/531
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections

Abstract

Improvements in the level of integration of a core buck and/or boost DC-DC voltage regulator sub-circuit lead to a lower manufacturing cost structure, an improved performance from lessened intrinsic parasitic resistance, a smaller die size and, thus, higher wafer yield. Further, by integrating certain components on-chip, the cost and complexity of the conventional hybrid circuit implementation is improved.

Claims

1. An integrated switching voltage regulator circuit comprising:

a diode anode layer of P-type semiconductor material;

a diode cathode layer of N-type semiconductor material formed on an upper surface of the diode anode layer such that the diode anode layer and the diode cathode layer combine to form a diode structure of the switching voltage regulator circuit;

a switching transistor formed over and extending into the diode cathode layer;

an inductor formed over the diode cathode layer and spaced apart therefrom by intervening dielectric material, the inductor also being spaced apart from the switching transistor;

a conductive interconnect structure disposed to electrically interconnect the diode structure, the switching transistor and the inductor, the conductive interconnect structure including a conductive voltage supply contact formed to extend from a lower surface of the diode anode layer through the diode anode layer and a portion of the diode cathode layer and into electrical contact with the switching transistor;

and wherein the switching voltage regulator circuit is adapted for connection to a capacitor.

2. An integrated switching voltage regulator circuit as in claim 1, and wherein the conductive interconnect structure comprises copper.

3. An integrated switching voltage regulator circuit as in claim 1, and wherein the conductive supply voltage contact comprises copper.

4. An integrated switching voltage regulator circuit as in claim 1, and wherein the inductor comprises a Permalloy inductor core and a copper inductor coil.

5. An integrated switching voltage regulator circuit as in claim 4, and wherein the switching transistor includes a copper source switching node that is connected to the copper inductor coil.

6. An integrated switching voltage regulator circuit as in claim 5, and wherein the copper source switching node is connected to the diode structure.

7. A method of making an integrated switching voltage regulator circuit, the method comprising:

forming a diode anode layer of P-type semiconductor material;

forming a diode cathode layer of N-type semiconductor material on an upper surface of the diode anode layer such that the diode anode layer and the diode cathode layer combine to form a diode structure of the switching voltage regulator circuit;

forming a switching transistor over and extending into the diode cathode layer;

forming an inductor over the diode cathode layer and spaced apart therefrom by intervening dielectric material, the inductor also being spaced apart from the switching transistor;

forming a conductive interconnect structure that electrically interconnects the diode structure, the switching transistor and the inductor, the conductive interconnect structure being formed to include a conductive voltage supply contact that extends from a lower surface of the diode anode layer through the diode anode layer and a portion of the diode cathode layer and into electrical contact with the switching transistor, and

wherein the switching voltage regulator circuit is adapted for connection to a capacitor.

8. A method as in claim 7, and wherein the conductive interconnect structure comprises copper.

9. A method as in claim 7, and wherein the conductive supply voltage contact comprises copper.

10. A method as in claim 7, and wherein the inductor comprises a Permalloy inductor core and a copper inductor coil.

11. A method as in claim 10, and wherein the switching transistor includes a copper source switching node that is connected to the copper inductor coil.

12. A method as in claim 11, and wherein the copper source switching node is connected to the diode structure.