Biochip for the capacitive stimulation and/or detection of biological tissue and a method for its production

• US 7,034,371 B2
• Filed: 11/03/2003
• Issued: 04/25/2006
• Est. Priority Date: 11/04/2002
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Schreiter, Matthias, Hofmann, Franz, Jenkner, Martin, Gabl, Reinhard, Eversmann, Björn
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): Mandala, Jr., Victor A.
• Application Number:
  US10/701,113
• Publication Number:
  US 20040119141A1
• Time in Patent Office: 904 Days
• Field of Search: 257/400, 257/252, 257/253, 257/288, 257/368, 257/414, 257/532, 257/535, 438/199, 438/957
• US Class Current: 257/414
• CPC Class Codes: G01N 27/414 Ion-sensitive or chemical field-effect transistors, i.e. ISFETS or CHEMFETS
• CPC Class Codes: G01N 33/4833 of solid biological material, e.g. tissue samples, cell cultures tissue in vivo A61B5/00; cell suspensions G01N33/48735
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

The present invention relates to a biochip for capacitive stimulation and/or detection of biological tissue. The biochip includes a support structure, at least one stimulation and/or sensor device, which is arranged in or on the support structure, and at least one dielectric layer, one layer surface of which is arranged on the stimulation and/or sensor device and the opposite layer surface forms a stimulation and/or sensor surface for the capacitive stimulation and/or detection of biological tissue. The dielectric layer includes (Ti_x, Zr_1-x)O₂, with 0.99≧x≧0.5, or a TiO₂ and ZrO₂ layer arrangement.

Claims

1. A biochip for capacitive stimulation and/or detection of biological tissue comprising:

a support structure;

at least one stimulation and/or sensor device arranged in or on the support structure; and

at least one dielectric layer, one layer surface of which is arranged on the stimulation and/or sensor device and the opposite layer surface of which forms a stimulation and/or sensor surface for the capacitive stimulation and/or detection of biological tissue;

wherein the dielectric layer includes (Ti_x, Zr_1-x)O₂, with 0.99≧

x≧

0.5, or a TiO₂ and ZrO₂ layer arrangement.

2. The biochip as claimed in claim 1, wherein the TiO₂ and ZrO₂ layer arrangement includes TiO₂ and ZrO₂ layers stacked alternately one on top of the other with a total number of (2n+1) layers (n≧

1), the outer layers being TiO₂ layers.

3. The biochip as claimed in claim 1, wherein the stimulation device includes a metal electrode, the electric potentional of which is externally controllable, and wherein the dielectric layer is arranged on the metal electrode.

4. The biochip as claimed in claim 1, wherein the support structure includes a semiconductor structure.

5. The biochip as claimed in claim 4, wherein the sensor device includes a field-effect transistor with a source contact, a drain contact, and a gate contact.

6. The biochip as claimed in claim 5, wherein the dielectric layer is arranged on a metal electrode of the sensor device which is connected in an electrically conductive manner to the gate contact of the field-effect transistor.

7. The biochip as claimed in claim 4, wherein the semiconductor structure is a CMOS semiconductor structure.

8. The biochip as claimed in claim 6, wherein the metal electrode is connected in an electrically conductive manner to the gate contact via an arrangement of metal and intermetal layers of the CMOS semiconductor structure.

9. The biochip as claimed in claim 4, wherein the dielectric layer forms the gate oxide of a field-effect transistor.

10. The biochip as claimed in claim 1, wherein the dielectric layer has an overall layer thickness of between 5 nm and 200 nm.

11. A method for producing a biochip for capacitive stimulation and/or detection of biological tissue, comprising the steps of:

providing a support structure;

forming at least one stimulation and/or sensor device in or on the support structure; and

arranging a dielectric layer of (Ti_x, Zr_1-x)O₂, with 0.99≧

x≧

0.5 or a TiO₂ and ZrO₂ layer arrangement on the stimulation and/or sensor device in such a way that one layer surface of the dielectric layer is arranged on the stimulation and/or sensor device and the opposite layer surface of the layer forms a stimulation and/or sensor surface for the capacitive stimulation and/or detection of biological tissue.

12. The method as claimed in claim 11, wherein the arranging of the dielectric layer is performed by sputtering a metallic titanium target and a metallic zirconium target in an argon/oxygen mixture.

13. The method as claimed in claim 11, wherein the step of arranging the dielectric layer includes the simultaneous sputtering of TiO₂ and ZrO₂, the substrate to be coated being arranged on a turntable in such a way that a (Ti_x, Zr_1-x)O₂ mixed oxide of a composition determined by the ratio of the generator outputs with which the titanium and zirconium targets are fed being deposited by the rotation of the turntable.

14. The method as claimed in claim 11, wherein the step of arranging the dielectric layer includes the sputtering of TiO₂ and ZrO₂ in such a way that TiO₂ and ZrO₂ layers are stacked alternately one on top of the other with a total number of (2n+1) layers (n≧

1), TiO₂ layers being deposited as the outer layers within the TiO₂ and ZrO₂ layer arrangement.

15. The method as claimed in claim 11, wherein the step of arranging the dielectric layer includes RF sputtering or sputtering with a pulsed DC source.

16. The method as claimed in claim 11, wherein the step of arranging the dielectric layer is performed as a back-end process step of a CMOS process.