QUANTUM DOT GATE FETS AND CIRCUITS CONFIGURED AS BIOSENSORS AND GENE SEQUENCERS

• US 20130140518A1
• Filed: 12/06/2012
• Published: 06/06/2013
• Est. Priority Date: 12/06/2011
• Status: Active Grant

• Current Assignee: Jain, Faquir C.
• Original Assignee: Jain, Faquir C.
• Inventors: Jain, Faquir C., Croce, Robert A. Jr., Jain, Anjana
• Granted Patent: US 8,853,667 B2
• Time in Patent Office: Days
• US Class Current: 257/12
• CPC Class Codes: B82Y 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors
• CPC Class Codes: G01N 27/4146 involving nanosized elements, e.g. nanotubes, nanowires
• CPC Class Codes: H01L 29/0684 characterised by the shape, relative sizes or dispositions of the semiconductor regions or junctions between the regions
• CPC Class Codes: H01L 29/66 Types of semiconductor device ; Multistep manufacturing processes therefor
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less

Abstract

Quantum dot (QD) gate FETs and the use of quantum dot (QD) gate FETs for the purpose of sensing analytes and proteins is disclosed and described. Analytes, proteins, miRNAs, and DNAs functionalized to the QDs change the charge density in the gate and hence the current-voltage characteristics. In one embodiment, QD-FETs, such as 3-state configurations, the binding of chemical and biological species change the drain current-gate voltage characteristics resulting in detection. In one embodiment, DNA sensing is done by its binding to an existing reference DNA functionalized on to quantum dots which are located in the gate region of the FET.

Claims

1. A bio sensor device comprising:

a field-effect transistor (FET) structure having a source, a drain, a gate region and a semiconductor substrate, wherein the semiconductor substrate includes a transport channel between the source and the drain and wherein the transport channel is controlled via a voltage applied to the gate region, and

wherein the gate region includes a multilayer structure having;

a first layer located adjacent to the transport channel, wherein the first layer is at least one of an insulator, a wide energy gap lattice matched semiconductor and a pseudomorphic semiconductor layer, wherein the first layer includes at least one layer of cladded quantum dots having an outer cladding layer, wherein the at least one layer of cladded quantum dot is constructed from the group comprised of SiO_x-cladded Si nanocrystal quantum dots and GeO_x-cladded Ge nanocrystal quantum dots, wherein the outer cladding layer is functionalized with a chemical group,

wherein the chemical group is bonded to recognition elements selected from a group comprising DNA, RNA, miRNA and antibodies, and wherein the recognition elements are bonded with target biomarkers including at least one of proteins, enzymes, and analytes; and

a top gate electrode fixed above the outer cladding layer to be in contact with a solution containing at least one target molecule.

2. The bio sensor device of claim 1, wherein the miRNA are detached using laser assisted heating once sensing is performed.

3. A biosensor device configured as a field effect transistor (FET) structure having a 3-state behavior, the biosensor device comprising:

a source, a drain and a gate region over a semiconductor substrate,

a transport channel located between the source and the drain and under the gate region, wherein the gate region is a multilayer structure having;

a first layer, identified as a barrier layer, located adjacent the transport channel and selected from the group consisting of a thin insulator, a wide energy gap semiconductor and lattice-matched pseudomorphic semiconductor layer,

wherein the first barrier layer includes a first layer and a second layer of SiO_x-cladded Si nanocrystal quantum dots having outer cladding layer, wherein the first layer and second layer of SiO_x-cladded Si dots have thin cladding of about 1-2 nm, and the wherein the Si cores are about 2-8 nm,

wherein the outer cladding layer of the second layer is functionalized with a chemical group, that is bonded to recognition elements constructed from at least one of DNA, RNA, miRNA and antibodies,

wherein the recognition elements are bonded with target biomarkers including at least one of proteins, enzymes, DNA, RNA, miRNAs, and analytes,

a top gate electrode located above the second layer in a solution containing at least one target molecule,

wherein the gate electrode is located over the functionalized SiO_x-cladded Si nanocrystal quantum dots, which controls the amount of charge located in the first layer and second layer of quantum dots, thereby rendering the field-effect transistor to serve as a 3-state device manifesting an intermediate state ‘

i’

in the transfer (drain current-gate voltage) characteristic.

4. The bio sensor device of claim 3, wherein the miRNA are detached using laser assisted heating once sensing is performed.

5. A field-effect transistor structure having a 3-state behavior and comprising a coupled quantum well channel in spatial wavefunction switched configuration, comprising:

a source, a drain, and a gate region, wherein the gate region comprises a multilayer structure,

a first thin insulator comprising of SiO₂, or wide energy gap lattice-matched semiconductor layer comprising of ZnMgS, ZnBeMgSSe of 10-100 Å

in thickness, wherein the first thin layer is adjacent to the semiconductor region between the source and drain regions, wherein the first thin insulator layer has at least two layers of cladded quantum dots deposited on it, the top surface of the cladded quantum dot layers has a gate semiconductor or metal layer, the layer comprising cladded quantum dots is made of SiO_x-cladded Si nanocrystals, and the semiconductor region under the first insulator layer comprises of a coupled quantum well structure,

wherein the coupled well structure is comprised of a strained Si layer serving as Well #1, a SiGe barrier, and second Si quantum well #2,

a second barrier layer located under the Si quantum well #2 which is constructed from SiGe and which is grown as a relative thick SiGe buffer layer in turn grown on a Si substrate,

wherein the outer cladding layer of second quantum dot layer is functionalized with a chemical group bonded to recognition elements constructed from at least one of DNA, RNA, miRNA and antibodies,

wherein the recognition elements are bonded with target biomarkers that include at least one of proteins, enzymes, and analytes,

a top gate electrode located above the functionalized layers in the solution containing target molecules, and

a gate control electrode over the functionalized SiO_x-cladded Si nanocrystal quantum dots, which controls the amount of charge located in the first layer and the second layer of quantum dots, thereby rendering the field-effect transistor to serve as a sensor using changes in drain current-gate voltage or drain current-drain voltage characteristics.