JPH0742126Y2 - ISFET inspection tool - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an I _DS -V _GS characteristic having V _DS of an ISFET (ion-sensitive field effect transistor) which is a kind of semiconductor ion sensor as a parameter or an I _DS having V _GS as a parameter. FET characteristic such as −V _DS characteristic and characteristic change p with respect to pH change
ISFE for measuring H characteristics, especially before assembly
The present invention relates to a T inspection tool.

[0002]

2. Description of the Related Art As an inspection method of this type, a portion other than a gate of an FET is covered with an insulating resin or the like and assembled as a finished product, and a lead wire of an inspection device connected to each electrode is also insulated. There is a method of immersing in an electrolyte solution in a container for inspection, or a method of immersing the solution in absorbent cotton or the like at the tip of the inspection tool and holding it by hand to bring it into contact with the gate section.

[0003]

[Problems to be Solved by the Invention] However, if the measurement is performed after the assembly as in the former method,
It takes time and labor, and a simple inspection is impossible. In the case of the latter method, since the liquid is brought into contact with the gate portion by holding the inspection tool by hand, there is a possibility that the measurement accuracy may be lowered or the measurement may be impossible due to the contact angle of the inspection device, the liquid being dried, or the liquid being excessive. Therefore, the present invention makes it possible to easily and accurately measure the FET characteristics or pH characteristics of the ISFET before assembly.
It is an object to provide an inspection tool for SFET.

[0004]

In order to achieve this object, the present invention provides, according to claim 1, a tip portion of a liquid reservoir and an electrolyte solution for inspection stored in the liquid reservoir to a gate portion by a capillary phenomenon. The present invention is characterized in that a core material having a shape suitable for the gate portion of the ISFET is attached and a lead wire for applying a voltage to the gate portion is led out from the core material through a liquid reservoir.

In order to easily supply the electrolyte solution to the liquid reservoir, the infusion tube for press-fitting the liquid is drawn out from the liquid reservoir according to the second aspect. In order to further improve the measurement accuracy, according to claim 3, a holder for detachably holding the liquid reservoir is attached.

[0006]

[Operation] When the gate of the ISFET is brought into contact with the core material of the inspection tool in which the electrolyte is filled in the liquid reservoir, the capillary fluid of the core causes the electrolyte to be constantly supplied from the liquid reservoir only to the facing gate portion. It

[0007]

1 shows an ISFET inspection tool according to an embodiment of the present invention. In the inspection tool 10, a liquid reservoir 12 is coaxially attached to a front side of a cylindrical base portion 11 held by a holding table 20,
A core material 13 is inserted into a cylindrical tip portion 12a which is deformed to a small diameter of the liquid reservoir. The holding table 20 is laterally movable, and has a cross section larger than a semicircle into which the base 11 is inserted. The slider 21 has a handle 21a formed with an elastic engaging portion 21b, and a handle 22a movable in the front-rear direction. The slider 22 with a slider and the slider 23 with a lock screw 23a that is movable in the vertical direction are combined so as to be slidable in three orthogonal directions.

The core material 13 has a capillary phenomenon,
For example, it is formed as one hollow fiber from porous water-absorbing PVA (polyvinyl alcohol). The core material is slightly exposed and is set to have a diameter corresponding to the width of the gate portion 5 (FIG. 2) of the ISFET 1a.
An Ag / Agcl wire is connected to the core member 13, and a lead wire 17 of a plug-in terminal 16 is led out from the liquid reservoir 12. The lead wire and the Ag / Agcl wire described above are connected in the inspection tool 10. Has been done. An infusion tube 14 is drawn out from the liquid reservoir 12.

In FIG. 2, reference numeral 1 is I before a plurality of cuts.
It is a wafer before assembly in which SFETs 1a are arranged, and each chip has a diode electrode 2, a source electrode 3, a drain electrode 4 and a gate portion 5, respectively.

At the time of inspection, as shown in FIG. 1, the wafer 1 is set on the inspection table, and the source electrode 3 and the drain electrode 4 are connected to the terminals of the lead wire led out from the inspection apparatus. On the other hand, the engaging portion 21b of the holding table 20 facing the wafer 1 is filled with the electrolyte solution for inspection with a press fitting tool such as a syringe through the liquid reservoir 12 through the infusion tube 14, and the insertion terminal 16 is also connected to the inspection device. The base 11 of the inspection tool 10 thus set is set. The holding table 20 is positionally adjusted in the three axial directions so that the electrolyte solution is surely exuded from the core material 13 by press fitting through the infusion tube 14 and is brought into contact with the gate portion 5 of the ISFET 1a to be inspected.

When the inspection is started, the gate portion 5 is dipped with the electrolyte solution for inspection in the same manner as when it is dipped in the container,
The FET characteristic or pH characteristic is measured. If the electrolyte solution in the gate section 5 is about to dry during the measurement, the solution automatically oozes out due to the capillary action of the core material 13 and is constantly immersed in the gate section 5 in an accurate positional relationship. There is no excess liquid.

When another ISFET 1a is measured, the wafer 1 is shifted, and if necessary, the holding table 20 is finely adjusted to restart the measurement. When the electrolyte solution is exhausted by repeated measurement, it can be replenished through the infusion tube 14. When the pH characteristic is measured, electrolyte solutions having different pH values are filled in advance in the liquid reservoir 12 of the individual inspection tool 10 and set on an individual holding table 20 at the time of measurement. When replacing the liquid in the liquid reservoir 12, the infusion tube 1
The electrolyte solution is pressed in through No. 4.

In the above-described embodiment, the infusion tube 14 led out from the liquid reservoir 12 of the inspection tool 10 can be omitted depending on the circumstances, and in this case, the liquid reservoir 12 is used as the base portion 1.
After removing from 1, and filling the liquid from the back, the base 11 can be mounted in a liquid-tight state. For the core material 13, it is possible to use a fiber bundle that exhibits a capillary phenomenon. Even when the test tool 10 is held by hand without being set on the holding table 20, a liquid pool 1 is provided as compared with the conventional hand-held test tool.
A stable liquid supply by the capillary phenomenon from 2 is guaranteed.

[0014]

As described above, according to the invention of claim 1, it is possible to easily immerse only the gate portion with the electrolyte solution for inspection without assembling it until the step of immersing it in the electrolyte solution. It can be constantly and stably supplied without being dried or excessive in the gate portion. Therefore, it is possible to secure a high degree of measurement accuracy without immersing it in the liquid in the container.
Repeated measurement is also possible by not drying. According to the second aspect of the invention, the electrolyte solution can be easily and surely press-fitted into the liquid reservoir through the infusion tube. According to the invention of claim 3, the position of the inspection tool is fixed, the measurement operation is simplified, and the measurement accuracy is further improved.

[Brief description of drawings]

FIG. 1 is a perspective view of an ISFET inspection tool according to an embodiment of the present invention.

FIG. 2 is a front view of a wafer of the ISFET.

[Explanation of symbols]

 1a ISFET 10 Inspection tool 12 Liquid reservoir 13 Core material 14 Infusion tube 20 Holding table

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location H01L 21/66 B 7630-4M L 7630-4M V 7630-4M

Claims (3)

[Scope of utility model registration request] 1. An ISFET inspection tool for measuring FET characteristics or pH characteristics, wherein the inspection electrolyte solution stored in the liquid reservoir is supplied to the gate portion by capillary action at the tip of the liquid reservoir. , And ISFET
An inspection tool for ISFET, characterized in that a core material having a shape corresponding to the gate portion is attached, and a lead wire for applying a voltage to the gate portion is led out from the core material through the liquid reservoir. 2. The ISFET inspection tool according to claim 1, wherein an infusion tube for press-fitting the electrolyte solution into the liquid reservoir is led out from the liquid reservoir. 3. The ISFET inspection tool according to claim 1, further comprising a holding table for detachably holding the liquid reservoir.