Heterojunction semiconductor flexible substrate, manufacturing method thereof, and electronic device using the same
Disclosed is a heterojunction semiconductor flexible substrate in which an epitaxial oxide thin film layer is hetero-bonded to a thinned silicon substrate using a metal layer, a manufacturing method thereof, and the heterojunction semiconductor flexible substrate can be applied to sensor, actuator, transducer, or micro electro mechanical systems (MEMS) device using high functionality of the epitaxial oxide thin film layer of high quality as well as an electronic and/or optical device.
1 . A heterojunction semiconductor flexible substrate in which an epitaxial oxide thin film layer is hetero-bonded to a thinned silicon substrate using a metal layer,
wherein the silicon substrate is a substrate which is thin-filmed in such a manner as to etch a lower silicon layer and a buried oxide (SiO 2 ) layer of a silicon-on-insulator (SOI) substrate, and
wherein the silicon substrate is a silicon-on-insulator (SOI) substrate in which a CMOS circuit is formed.
2 . The substrate of claim 1 , wherein the epitaxial oxide thin film layer and the metal layer are patterned in a plurality of lattice cells.
3 . The substrate of claim 1 , wherein the epitaxial oxide thin film layer is a piezoelectric oxide having a perovskite structure.
4 . The substrate of claim 1 , wherein the metal layer has a single layer structure or a layered structure composed of one element, or two or more of elements selected from a group consisting of Au, Al, W, Ti, Cr, Pt, Cu, Ni, Mo, Ta, Nb, and La.
5 . The substrate of claim 4 , wherein the layered structure is a structure in which a layer A, a layer B, and a layer A′ are laminated in order, the layer of A and the layer of A′ are identical to or different from each other and are any one selected from the group consisting of Ti, Cr, Cu, Ni, Pt, and Cr, and the layer of B is any one selected from the group consisting of Au, Mo, Ta, Nb, La, W, and CuW.
6 . The substrate of claim 5 , wherein the metal layer has the layered structure of the layer of A, the layer of B, and the layer of A′ that are laminated in order, the layer of A and the layer of A′ each consist of a metal adhesion layer having a thickness of 5 nm to 20 nm, and the layer of B consists of a metal bonding layer having a thickness of 20 nm to 1 μm.
7 . The substrate of claim 1 , wherein a conductive metal oxide layer is further formed between the epitaxial oxide thin film layer and the metal layer.
8 . The substrate of claim 7 , wherein the conductive metal oxide layer comprises metal which is able to form Schottky contact with the epitaxial oxide thin film layer.
9 . The substrate of claim 7 , wherein the conductive metal oxide layer is amorphous or has a crystalline structure.
10 . An electronic device comprising a heterojunction semiconductor flexible substrate of claim 1 , which is applied to any one of a group selected from the group consisting of an electro-electronic device, optical device, sensor, actuator, transducer, and micro-electromechanical system (MEMS) device.