JPS61234348A - Manufacture of semiconductor biosensor - Google Patents

Abstract

PURPOSE:To enable massproduction of biosensors, by a method wherein an enzyme immobilized film and a photoresist layer are formed on a semiconductor wafer with an ion sensor formed thereon and then, the photoresist layer and the enzyme immobilized film are removed except for necessary portion. CONSTITUTION:An ion induction section 2 of an FE type ion sensor is provided on the top surface of a sapphire substrate 1 while a gold electrode 5 on the undersurface thereof. An enzyme immobilized film 3 and a photoresist layer 4 are formed over the entire surface on the side of the ion induction section 2. Then, a photomask is used to remove the photoresist layer 4 except for the surface of the ion induction section 2 by exposure and development and then, the work is immersed into an aqueous solution of crude trypsin or the like to decompose the enzyme-immobilized film 3. Thereafter, a biosensor with an eyzyme film at a specified ion induction section alone by removing the photoresist layer 4. Thus, a massproducible fine one-chipped sensor can be obtained by applying an IC production technology.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a plurality of ion-sensing parts on one chip,
The present invention relates to a method for manufacturing a semiconductor biosensor in which an enzyme membrane is partially formed.

[Conventional technology]

Assuming that one chip has two ion-sensitive areas and only one has enzyme activity, the present inventors formed an enzyme film on the entire surface and then exposed light to a predetermined ion-sensitive area. proposed a method of deactivating enzymes by irradiating them with ultraviolet rays using a photomask made of
No. 3”).

[Problems that the invention attempts to solve]

This method has an advantage as a method of partially imparting activity in order to control the enzyme activity in the immobilized enzyme membrane, but basically different types of enzyme immobilized membranes are placed independently in different locations on the same wafer. It is difficult to create.

In addition, as a means to overcome the above-mentioned drawbacks, a method was proposed in which a minute amount of enzyme solution was directly dropped onto the ion-sensitive area to form an enzyme film only in a predetermined area (Japanese Patent Application No. 59-20862
6), but requires minute mechanical operations.

Furthermore, in order to overcome the above-mentioned drawbacks, we proposed a method of turning the enzyme membrane by lift-off.
9-209165'', ``% Application No. 59-209166''). Although this method is effective as a method for easily realizing continuous turning of an enzyme membrane, patterning becomes difficult when the thickness of the immobilized enzyme membrane exceeds a certain level.

An object of the present invention is to provide a method for manufacturing a semiconductor biosensor in which an enzyme membrane is provided only in a predetermined ion-sensitive area by decomposing and removing unnecessary enzymes or the enzyme membrane itself under mild conditions.

[Level for solving problems]

The present invention provides a method for producing a biosensor in which a plurality of ion-sensitive parts are formed on one chip and at least one type of enzyme is immobilized, in which an enzyme-immobilized film is formed over the entire surface of a semiconductor wafer on which an ion sensor is formed. a step of forming a photoresist layer on the enzyme-immobilized membrane in the part that corresponds to the ion-sensing part of the ion sensor; a step of decomposing the enzyme or the enzyme-immobilized membrane itself using a protease; This is a method for manufacturing a semiconductor biosensor, which includes a step of removing a layer.

〔Example〕

An embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) to 1(f) are diagrams for explaining one embodiment of the method for manufacturing a semiconductor biosensor according to the present invention, and are cross-sectional views of the ion-sensitive membrane portion in each step.

The figure shows a field-effect ion sensor Ion 5ensistiveFl, which has an enzyme-immobilized membrane on a sapphire substrate.
eld Effect Transi@tor (l5
The case where this is formed into an I5FET without a chip is shown. Note that the metal reference electrode is deposited on the back surface of the sapphire substrate. Figure 1(a)
In ~(f), 1 is a sapphire substrate, 2 is an ion sensitive part of a field-effect ion sensor, 3 is an enzyme-immobilized membrane, and 4 is a sapphire substrate.
is a photoresist layer, and 5 is a gold electrode. Next, the manufacturing process will be explained step by step. In FIG. 1 (&), first, an 18FET 2 is formed using an island-like microcon layer on the surface of a sapphire substrate 1, a gold electrode 5 is attached to the back surface of the sapphire substrate 1 by vapor deposition of gold, and an enzyme is further applied to the surface. An enzyme-immobilized film 3 is formed by spin-coating a protein solution containing a cross-linking agent and a cross-linking agent. For example, when detecting urea, add 250 µm of 0.2 M, pH 8.5 Tris-HCl buffer containing 15% bovine serum albumin to 100 μl prepared with the same buffer.
Add 250 pi of 001n9/11 urease (manufactured by Perinsee Mannheim, approx. 50 V/I 11 g) solution, and mix this with 500 pi of 0.751 glutaraldehyde aqueous solution.
Use a solution mixed with μ. Next, an acetone-soluble photoresist such as AZ 1450 J manufactured by Silagray Co., Ltd. is spin-coated on the surface of the enzyme-immobilized membrane 3 (see Fig. 16).
A photoresist film 4 is formed as shown in FIG. Further, by exposure and development using a photomask, the photoresist film 4 is removed from a portion other than the surface of the 15FET 2 on which the enzyme immobilization film 3 is provided, as shown in FIG. 1(c). This wafer'k
The enzyme-immobilized membrane 3 is decomposed by immersion in a crude trypsin aqueous solution of 11/It for 1 minute (FIG. 1(d)). Thereafter, the photoresist is immersed in an aqueous trypsin inhibitor solution to stop the proteolysis reaction, and then immersed in acetone to dissolve the photoresist (FIG. 1(e)). The wafer is cut to obtain individual senna as shown in FIG. 1(f).

The thickness of the enzyme-immobilized film 3 obtained by this method can be controlled by controlling the solution concentration and rotation speed during spin coating. Although the adhesion of the enzyme-immobilized membrane 3 to the ion-sensitive membrane in this example was good, it is also possible to perform primer treatment before spin coating to further improve the adhesion.

In this example, a minute biosensor with a width of 0.6 mm and a length of 4 mm was obtained.

[Effects of the Invention] According to the present invention, IC manufacturing technology can be applied, mass production is possible, and a microscopic single-chip biosensor can be manufactured.

Further, the present invention provides I5F formed on a sapphire substrate.
Not limited to ET, 5OI (5i
licon on Ingnlator) structure l5
It is clear that the present invention can also be applied to FETs, bulk 51t-based 15FETs, and minute amperometric electrodes.

[Brief explanation of the drawing]

FIGS. 1(a) to 1(r) are diagrams for explaining one embodiment of the method for manufacturing a semiconductor biosensor according to the present invention, and are cross-sectional views of the ion sensing portion of the ion sensor in each step. DESCRIPTION OF SYMBOLS 1... Sapphire substrate, 2... Ion sensitive part of ion sensor, 3... Enzyme immobilization membrane, 4... Photoresist film, 5... Gold electrode. Figure 1

Claims (1)

[Claims] (1) Forming multiple ion-sensitive parts on one chip,
A method for manufacturing a biosensor in which at least one enzyme is immobilized includes a step of forming an enzyme-immobilized film on the entire surface of a semiconductor wafer on which an ion sensor is formed, and immobilizing the enzyme on a portion corresponding to the ion-sensing part of the ion sensor. A method for manufacturing a semiconductor biosensor, which comprises the steps of forming a photoresist layer on a film, decomposing the enzyme or the enzyme-immobilized film itself using a protease, and removing the photoresist layer.