Field-Effect Device for the Detection of Small Quantities of Electric Charge, Such as Those Generated in Bio-Molecular Process, Bound in the Vicinity of the Surface

• US 20070247170A1
• Filed: 06/09/2005
• Published: 10/25/2007
• Est. Priority Date: 06/09/2004
• Status: Active Grant

• Current Assignee: Conversant Intellectual Property Management Inc (MOSAID Technologies Inc. (f/k/a Conversant Intellectual Property Management))
• Original Assignee: Consiglio Nazionale Delle Ricerche-Infm Istituto Nazionale Per La Fisica Della Materia
• Inventors: Bonfiglio, Annalisa, Raffo, Luigi, Barbaro, Massimo
• Granted Patent: US 7,535,232 B2
• Time in Patent Office: Days
• US Class Current: 324/653
• CPC Class Codes: G01N 27/4145 specially adapted for biomolecules, e.g. gate electrode with immobilised receptors

Abstract

The device (1) allows the detection of small quantities of electrical charge (Qs) utilised for recognition of the gybridisation process of a single strand of DNA. It comprises a chip (2) in which is integrated an MOS device having a floating gate (7) a first portion (7a) of which extends in facing relation to a recess (8) formed in a surface of the chip (2) and accessible from outside the chip (2) and operable to retain an electrical charge (Qs) to be measured bound to it. A second portion (7b) of the gate (7) of the MOS device is coupled to a control electrode, (10) of the chip (2) by means of a capacitor (12) of predetermined value within the chip (2).

Claims

1. A device (1) for detecting small quantities of electrical charge (Qs) comprising a chip (2) in which is integrated a MOS device having a floating gate (7) a first portion (7a) of which extends in facing relation with a recess (8) formed in the surface of the chip (2) and accessible from outside the chip (2) and able to retain an electrical charge (Qs) to be measured bound to it;

a second portion (7b) of the gate (7) of the said device MOS being coupled to a control electrode (10) of the chip (2) by means of a capacitor (12) of predetermined value within the chip (2).

2. A device according to claim 1, in which the said chip (2) is formed with a standard CMOS process.

3. A device according to claim 1, in which the said first portion (7a) of the floating gate (7) is at least partially covered by a layer of interface material (9) which can bind an electrically charged material applied to it.

4. A device according to claim 1, in which the said second portion (7b) of the floating gate (7) is capacitively coupled to an overlying supplementary layer (11) of conductive material, for example polysilicon connected to a control electrode (10) accessible from outside the device (1).

5. A device according to a claim 1, in which the said MOS device comprises a substrate (3) of semiconductor material with p-type doping, and in which the said second portion (7b) of the floating gate (7) is capacitively coupled to a zone (13) of this substrate (3) which has an n+ type doping and which is connected to a control electrode (10) accessible from outside the device (1).

6. A device for the detection of small quantities of electrical charge such as that generated in bio-molecular processes, substantially as described and illustrated, and for the specified objects.