JPS6188135A - Production of semiconductor biosensor - Google Patents

Abstract

PURPOSE:To form easily integrated micro semiconductor biosensors by integrating the plural semiconductor field effect type ion sensors on one chip. CONSTITUTION:A photoresist film 6 soluble in acetone is spin-coated on the surface of a wafer constituted by forming the semiconductor field effect type ion sensors ISFETs by using an island-shaped silicon layer on the front of a sapphire substrate 1 and depositing gold 8 by evaporation on the rear. The photoresist film on the surface of the ISFETs to be provided with an enzyme immobilizing film is removed by exposing and developing in using a photomask and thereafter a protein soln. 7 contg. enzyme and crosslinking agent is spin- coated thereon. The water is then immersed in acetone to dissolve the photoresist 6 and at the same time the enzyme immobilizing film 7 coated on the photoresist is removed. The wafer is thereafter scribed, by which the semiconductor biosensors are obtd.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a semiconductor biosensor, and in particular to an integrated semiconductor biosensor in which an enzyme-immobilized membrane is provided on the surface of a semiconductor field-effect ion sensor. The present invention relates to a method of manufacturing a sensor.

(Prior Art) Conventionally, a semiconductor field effect ion sensor is a type of semiconductor biosensor that measures the concentration of a specific organic substance in a solution.
Transistor (hereinafter abbreviated as l5FFiT) is known to have a membrane on which enzymes are immobilized (Yuji Miyahara, Shoko Shioyo, Toyosaka Moriizumi, and Hideaki Matsuoka).

Yukio Karube, Shu Suzuki: "Biosensor using semiconductor technology", Institute of Electronics and Communication Engineers Electronic Components and Materials Study Group Material CPM8
1-93, 61 (1981)) This 15FET biosensor detects the change in hydrogen ion concentration in the membrane that occurs when a specific organic substance in a solution is decomposed by the catalytic action of the enzyme in the enzyme-immobilized membrane. This method measures the concentration of specific organic substances by detecting them. Examples of enzyme-immobilized membranes having this selectivity include urease-immobilized membranes for urea detection and glucose oxidase-immobilized membranes for glucose detection.

However, by measuring the difference in output between the ISB'ET with an enzyme-immobilized membrane and the 15FET without it, it is possible to cancel out the effects of potential changes in the solution, and In recent years, it has been reported that metal electrolytes are used for diagnostic electric appliances.

Hanazato and S, 5hiono:
Bioelectrode Vsing TVOHydr
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5isters and a Platinum wi
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Reference Electrode, Pro
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eating on Che+n1cal Sansor
s, P, 513 (1983)) (Problems with the Prior Art) However, the conventionally known semiconductor biosensor is formed by attaching individual xsrgT or gold scrap reference electrodes to the substrate, and the l5FET There was a drawback that the advantages of integration and miniaturization by applying IC technology, which are the characteristics of ISF'ET and l5FET
An object of the present invention is to provide a method for manufacturing an integrated microscopic semiconductor biosensor by easily forming on the same chip. In a method for manufacturing a semiconductor biosensor, in which a plurality of semiconductor field-effect ion sensors are integrated, and an enzyme-immobilized film is provided on the surface of at least one of the semiconductor field-effect ion sensors, the semiconductor field-effect ion sensor is A step of applying a photoresist on a semiconductor wafer on which a sensor is formed, and then using a photophosphorography method to remove the photoresist on the surface of a given semiconductor field effect ion sensor on which an enzyme-immobilized film is provided, and an enzyme and a crosslinking agent. The present invention is characterized by comprising a step of applying a protein solution containing a protein solution to form an enzyme-immobilized film, and a step of dissolving the photoresist and removing the enzyme-immobilized film existing on areas other than the surface of a predetermined semiconductor field-effect ion sensor. A method for manufacturing a semiconductor biosensor is obtained.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1 to 4 are cross-sectional views of main steps for explaining an embodiment of the method for manufacturing a semiconductor biosensor according to the present invention. The figure shows a tS FET with an enzyme-immobilized membrane provided on a sapphire substrate and an l8 without it.
In the case shown for forming an FET, a metal reference electrode is deposited on the back side of the sapphire substrate.

1 to 4, 1 is a sapphire substrate, 2 is a highly impurity n-type silicon region, 3 is a p-type silicon region,
4 is a silicon oxide film, 5 is a silicon nitride model, 6 is an acetone-soluble photoresist film, and 7 is an enzyme-immobilized film 8 which is a gold electrode. Follow the manufacturing process step by step and use the layers 18
An acetone-soluble raw photoresist (Z1450J manufactured by Silaplay Co., Ltd.) was spin-coated on the surface of the wafer on which FETs were formed and gold 8 was vapor-coated on the back surface of the sapphire group (see FIG. 1).

After exposure and development using a photomask, the photoresist film on the surface of the 18FET on which the enzyme-immobilized film was provided was removed (Fig. 2).After that, in order to detect urea as an example of a protein solution containing an enzyme and a crosslinking agent, 100 mg/d mixed with the same buffer in 250 μl of 0.2 M, p[(8,5) Tris-HCl buffer containing 15% bovine serum albumin.
l urease (manufactured by Peringer Mannheim, approx. 50
A solution prepared by adding 1250 μl of V/mg) and stirring and mixing with 500 μl of a 0.75% geltaraldehyde aqueous solution was applied by spin coating (Figure 3). As another example, in order to detect glucose, an enzyme-immobilized membrane was created using glucose oxidase as an enzyme. In addition, it is possible to use ordinary enzyme-immobilized membranes in a similar manner.

In this example, the enzyme-immobilized film had a good thickness of 5000X or less, but it is also possible to perform primer treatment before spin-coating the enzyme-immobilized film in order to further improve the layer density. After this, the wafer is immersed in acetone to dissolve the photoresist, and at the same time, the enzyme immobilization film coated on the photoresist is removed. Since the enzyme in the enzyme-immobilized membrane was not inactivated by acetone, an active enzyme-immobilized membrane could be formed only on the surface of a given 15FET by this step (FIG. 4). Thereafter, by scribing the wafer, the semiconductor biosensor shown in FIGS. 5 and 6 is completed. FIG. 5 is a plan view, and FIG. 6 is a sectional view of the sensor section. Chip size is 0-6mm, length 4
A minute biosensor was obtained.

(Effects of the Invention) According to the present invention, IC manufacturing technology can be applied, and a microscopic integrated semiconductor biosensor that can be mass-produced can be manufactured.

The present invention is not limited to 15FETK formed on a sapphire substrate, but is also applicable to 8QI (S-eye 1co) using a general PJ substrate.
It is clear that it can also be applied to 18FETs with a non-5apphire structure and 15FETs using bulk Si. It is a figure for explaining. Figure 1~
In FIGS. 4 and 6, 1 is a sapphire substrate, and 2 is a high impurity 5 degree. 3 is a p-type silicon region, 4 is a silicon oxide layer, 5 is a silicon nitride film, 6 is an acetone-soluble photoresist layer, 7 is an enzyme immobilization film, 8
9 is a gold electrode, 9 is a 15FET, and 10 is an electrode.

Procedural amendment (formality) :j+, :j’.

Claims (1)

[Claims] A method for manufacturing a semiconductor biosensor, in which a plurality of semiconductor field-effect ion sensors are integrated on one chip, and an enzyme-immobilized film is provided on the surface of at least one semiconductor field-effect ion sensor. A step of removing the photoresist from the surface of a predetermined semiconductor field-effect ion sensor, in which a photoresist is applied on a semiconductor wafer on which a field-effect ion sensor is formed, and then an enzyme-immobilized film is provided by a photolithography method; The method includes a step of applying a protein solution containing a cross-linking agent to form an enzyme-immobilized film, and a step of dissolving the photoresist and removing the enzyme-immobilized film existing on areas other than the surface of a predetermined semiconductor field-effect ion sensor. A method for manufacturing a semiconductor biosensor characterized by: