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Browse Prior Art Database

Superconducting Field-Effect Transistor

IP.com Disclosure Number: IPCOM000062582D
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 27K

Publishing Venue

IBM

Related People

Jackson, TN: AUTHOR

Abstract

The use of polycrystalline InAs or InSb can provide an easily contacted superconducting field-effect transistor. The procedure is shown in Figs. 1-6. A metal layer is placed on a substrate, such as Al2O3 . The metal should be superconducting at the temperature of desired device operation, as shown in Fig. 1. As shown in Fig. 2, undoped InAs or InSb is deposited on the metal layer, for example, by molecular beam epitaxy (MBE). It will grow polycrystalline since the metal is not a suitable surface for epitaxy. In Fig. 3, a second layer of metal is deposited. This metal should also be superconducting at the operation temperature. As shown in Fig. 4, the metal-semiconductor-metal sandwich is patterned, for example, by photolithography and reactive ion etching. As shown in Fig.

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Superconducting Field-Effect Transistor

The use of polycrystalline InAs or InSb can provide an easily contacted superconducting field-effect transistor. The procedure is shown in Figs. 1-6. A metal layer is placed on a substrate, such as Al2O3 . The metal should be superconducting at the temperature of desired device operation, as shown in Fig.
1. As shown in Fig. 2, undoped InAs or InSb is deposited on the metal layer, for example, by molecular beam epitaxy (MBE). It will grow polycrystalline since the metal is not a suitable surface for epitaxy. In Fig. 3, a second layer of metal is deposited. This metal should also be superconducting at the operation temperature. As shown in Fig. 4, the metal-semiconductor-metal sandwich is patterned, for example, by photolithography and reactive ion etching. As shown in Fig. 5, an insulator is deposited on at least the vertical face of the patterned sandwich. This may be done by conformal chemical vapor deposition or by directional sputtering. The device is completed as shown in Fig. 6 with a metal deposited at least against the insulated vertical face of the patterned sandwich. The resulting device is a polycrystalline edge Josephson junction field-effect transistor (FET). Enhancement-type FETs are made by inducing a conductive channel at the insulator-polycrystalline semiconductor interface by action of the metal gate electrode. Depletion FETs are made by doping the exposed surface of the semiconductor shown in Fig. 4 by di...