Patent ID: 6908771

Claim:
A method for fabricating a dc superconducting quantum interference device, the method comprising the steps of: (a) adhering a high-Tc superconducting single crystal layer on a first insulating substrate by using a first adhesion layer; (b) cutting away the single crystal layer to form a platform with a first thickness and cutting away a first portion of the platform to generate a platform layer, wherein the portion of the platform layer has a second thickness which is close to ½ of the first thickness; (c) adhering the platform layer on a second insulating substrate by using a second adhesion layer to form a stacking structure sequentially having the first insulating substrate, the first adhesion layer, the platform layer, the second adhesion layer and the second insulating substrate; (d) detaching the first insulating substrate from the stacking structure to expose the platform layer and forming a metal layer on the platform layer; (e) cutting away respective portions from both the metal layer and the platform layer to form an intrinsic Josephson junction layer having intrinsic Josephson junctions therein; (f) patterning the platform layer to form a ring-shaped platform layer so that the intrinsic Josephson junction layer in the platform layer is divided into two intrinsic Josephson junction portions in the ring-shaped platform layer; and (g) attaching at least two current electrodes for applying a current into the circular platform layer and attaching at least two voltage electrodes for detecting a voltage difference across said two stacks of intrinsic Josephson junctions.