Composite GaAs-on-quartz substrate for integration of millimeter-wave passive and active device circuitry

• US 5,276,345 A
• Filed: 10/30/1992
• Issued: 01/04/1994
• Est. Priority Date: 10/30/1992
• Status: Expired due to Fees

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Wilson, Barbara, Mehdi, Imran, Siegel, Peter H.
• Primary Examiner(s): Hille, Rolf
• Assistant Examiner(s): SAADAT, MAHSHID D
• Application Number:
  US07/969,472
• Time in Patent Office: 431 Days
• Field of Search: 257/347, 257/352, 427/96.99, 437/83, 437/84
• US Class Current: 257/352
• CPC Class Codes: H01L 21/6835 using temporarily an auxiliary support
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 27/0605 integrated circuits made of compound material, e.g. AIIIBV
• 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 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12032 Schottky diode
• CPC Class Codes: H01L 2924/13063 Metal-Semiconductor Field-Effect Transistor [MESFET]
• CPC Class Codes: H01L 2924/14 Integrated circuits

Abstract

The lift-off technique for transferring a preprocessed GaAs circuit to a quartz carrier is used to integrate GaAs active devices with distributed quartz microwave circuit elements (e.g., microstrip circuitry) in a single integrated circuit package. The present invention is therefore useful in making a variety of extremely rugged, low loss millimeter and submillimeter wave integrated circuits. By restricting the GaAs layer to a thin membrane and by impurity-doping the GaAs layer only in the regions of the active devices, the advantages of the quartz substrate in the presence of millimeter wave or submillimeter wave radiation are essentially retained.

Claims

1. An integrated circuit operable in the millimeter to submillimeter wavelength range, comprising:

a quartz substrate;

an epitaxially lifted-off GaAs layer bonded to a top surface of said substrate wherein said lifted-off GaAs layer covers less than all of said top surface of said substrate;

plural semiconductor circuit elements formed on said GaAs layer; and

distributed passive circuit elements responsive in the millimeter to submillimeter wavelength range wherein said distributed passive circuit elements comprise top layer metalization patterns formed directly on said quartz substrate.

2. The integrated circuit of claim 1 wherein said semiconductor circuit elements comprise GaAs diodes.

3. The integrated circuit of claim 1 wherein said distributed passive circuit elements comprise microstrip circuit elements.

4. The integrated circuit of claim 1 further comprising means for electrically connecting said semiconductor circuit elements to said distributed passive circuit elements.

5. The integrated circuit of claim 1 wherein said lifted-off GaAs layer is formed by the process of forming said epitaxial layer on a host GaAs substrate and lifting off said epitaxial layer from said substrate.

6. The integrated circuit of claim 1 wherein said lifted-off GaAs layer is molecularly bonded to said quartz substrate.

7. The integrated circuit of claim 1 wherein said lifted-off GaAs layer is bonded by an adhesive substance to said quartz substrate.

8. An enhanced integrated circuit, comprising:

a major GaAs integrated circuit substrate comprising plural interconnected semiconductor circuit elements at a top surface thereof; and

a lifted-off GaAs, epitaxial layer comprising semiconductor circuit elements connectable to said semiconductor circuit elements of said major GaAs integrated circuit substrate and bonded to said top surface of said major GaAs integrated circuit substrate, said lifted-off GaAs epitaxial layer being at least one order of magnitude less in thickness than said major GaAs integrated circuit substrate whereby to provide ultra-thin semiconductor circuit elements for said integrated circuit.

9. The integrated circuit of claim 8 wherein said lifted-off GaAs layer is formed by the process of forming said epitaxial layer on a host GaAs substrate and lifting off said epitaxial layer from said substrate.

10. The integrated circuit of claim 8 wherein said lifted-off GaAs layer is molecularly bonded to said GaAs integrated circuit substrate.

11. The integrated circuit of claim 8 wherein said lifted-off GaAs layer is bonded by an adhesive substance to said GaAs integrated circuit substrate.