JPH10239195A - Semiconductor pressure sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor pressure sensor that can be made small in size while forming p-type resistors and electrode pads for measuring reverse voltage-current characteristics. SOLUTION: The semiconductor pressure sensor is constituted by forming a diaphragm 12 serving as a pressure receiving part on a silicon substrate 11, and gauge resistors and electrode pads 23-26 on the surface side of the diaphragm 12. Resistors and electrode pads 5 for measuring the reverse characteristics of p-n junction between the gauge resistor and the diaphragm 12 are formed in the dicing lane 4 of the silicon substrate 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor pressure sensor having a diaphragm formed on a semiconductor substrate.

[0002]

2. Description of the Related Art A semiconductor pressure sensor transmits a pressure to be detected as a strain to a silicon thin film of a diaphragm composed of a silicon thin film, changes a resistance value of a gauge resistor formed on the diaphragm, and converts this change into an electric signal. By detecting, the pressure is detected.

In this type of semiconductor pressure sensor, four gauge resistors are formed by diffusing or ion-implanting a p-type impurity such as silicon on a diaphragm formed on an n-type silicon substrate. A bridge circuit is formed by bridge-connecting the resistors, and a detection voltage corresponding to the measured pressure can be obtained as an output of the bridge circuit.

In such a semiconductor pressure sensor, the current applied to the bridge circuit usually flows through the gauge resistor, but the leak current (p−
The presence of an n-junction reverse current) causes errors in the measured pressure values. Therefore, in the manufacturing process of the semiconductor pressure sensor, it is important to check the reverse voltage-current characteristic of the pn junction, and the quality of the semiconductor pressure sensor is determined based on the reverse voltage-current characteristic. A specific example of a method for checking the reverse voltage-current characteristics is disclosed in
-733. That is, as shown in FIG. 2, one semiconductor pressure sensor 1 among a plurality of semiconductor pressure sensors formed on a silicon wafer has a diaphragm 12 formed at a central portion of an n-type silicon substrate 11. Four p-type gauge resistors 13 to 16 are formed by diffusion or ion implantation, respectively. Each of the gauge resistors 13 to 16 is bridge-connected to form a bridge circuit. Bonding pads (electrode pads) 23 to 26 made of Al electrodes for external electric measurement are formed on the gauge resistors 13 to 16 by vapor deposition or the like. Further, on the outside of the diaphragm 12 in the effective area of the semiconductor pressure sensor 1 on the silicon substrate 11, a p-type resistor 17 and an Al electrode on the P-type resistor 17 are formed in the same manner as the gauge resistors 13 to 16. A bonding pad (electrode pad) 27 for measurement is formed, and a reverse voltage-current characteristic measurement of the pn junction is performed using the p-type resistor 17 and the bonding pad 27. The p-type resistor 17 is independent of the bridge circuit and has a floating island shape.

In the semiconductor pressure sensor 1 thus formed, as shown in FIG.
6 and the p-type resistor 17, a direct current is applied from the measuring device 3 through the bonding pads 23 to 26 for external electrical connection and the bonding pad 27 for measurement made of an Al electrode, and the leak current is reduced. By measuring
The reverse voltage-current characteristics of the pn junction are measured.

[0006]

However, in the above-described semiconductor pressure sensor, the area occupied by the bonding pad 27 of the p-type resistor 17 for measuring the reverse voltage-current characteristics in the semiconductor pressure sensor 1 is large. Since it is large, there is a problem that it is difficult to reduce the size of the semiconductor pressure sensor 1 itself.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to reduce the size while forming a p-type resistor and an electrode pad for measuring reverse voltage-current characteristics. It is an object of the present invention to provide a semiconductor pressure sensor which is enabled.

[0008]

According to a first aspect of the present invention, there is provided a semiconductor pressure sensor comprising a diaphragm serving as a pressure receiving portion formed on a silicon substrate, and a gauge resistor and an electrode pad formed on a surface side of the diaphragm. Wherein a resistance for measuring reverse characteristics of a pn junction between the gauge resistance and the diaphragm and an electrode pad for measurement are formed in a dicing lane of the silicon substrate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a semiconductor pressure sensor according to an example of an embodiment of the present invention. The basic configuration of the semiconductor pressure sensor according to the present embodiment is the same as that described in the related art, and therefore, the same portions are denoted by the same reference numerals and description thereof will be omitted. The feature of this embodiment is that the p-type resistor and the bonding pad (electrode pad) for measuring the reverse voltage-current characteristics are formed in the dicing lane outside the effective area of the semiconductor pressure sensor. That is, as shown in FIG. 1, a plurality of semiconductor pressure sensors 1 are formed on a silicon wafer S, and a dicing lane 4 is formed between adjacent semiconductor pressure sensors 1. Each semiconductor pressure sensor 1 formed on the silicon wafer S is cut off by dicing along the dicing lane 4. The dicing lane 4 is a cutting margin, and is outside a rectangular area effective as the semiconductor pressure sensor 1. In the dicing lane 4, a p-type resistor and a bonding pad 5 for measuring a reverse voltage-current characteristic are formed corresponding to each semiconductor pressure sensor 1.
The p-type resistor and the bonding pad 5 are formed in the same manner as the gauge resistors 13 to 16 and the bonding pads 23 to 26.

Using a p-type resistor and a bonding pad 5 for measuring a reverse voltage-current characteristic for each semiconductor pressure sensor 1 of the silicon wafer S, a reverse voltage-voltage is measured in the same manner as shown in FIG. The current characteristics are measured. After the measurement, each semiconductor pressure sensor 1 may be separated by dicing along the dicing lane 4.

As described above, according to the present embodiment, the p-type resistor and the bonding pad 5 for measuring the reverse voltage-current characteristics are formed on the dicing lane 4 outside the effective area of the semiconductor pressure sensor 1. Therefore, as in the conventional case, the reverse voltage −
There is no need to form a p-type resistor and a bonding pad for measuring current characteristics, so that the reverse voltage-current characteristics can be measured in the same manner as in the past, and the semiconductor pressure sensor 1
Size can be reduced.

[0012]

As described above, according to the first aspect of the present invention, there is provided a semiconductor pressure sensor having a diaphragm as a pressure receiving portion formed on a silicon substrate, and a gauge resistor and an electrode pad formed on the surface side of the diaphragm. In the sensor, the resistance for measuring the reverse characteristics of the pn junction of the gauge resistance and the diaphragm and the electrode pad for measurement are formed in the dicing lane of the silicon substrate, so that the measurement for the reverse voltage-current characteristics is performed. A semiconductor pressure sensor capable of miniaturization while forming a p-type resistor and an electrode pad was provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a semiconductor pressure sensor according to one embodiment of the present invention.

FIG. 2 is a schematic view showing a semiconductor pressure sensor according to a conventional example.

FIG. 3 is an explanatory diagram showing a measurement state of a reverse voltage-current characteristic of a semiconductor pressure sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor pressure sensor 3 Measuring device 4 Dicing lane 5 Bonding pad 11 Silicon substrate 12 Diaphragm 13-16 Gauge resistance 17 P-type resistance 23-27 Bonding pad

Claims (1)

[Claims] 1. A semiconductor pressure sensor comprising: a silicon substrate having a diaphragm serving as a pressure receiving portion; and a gauge resistor and an electrode pad formed on a surface of the diaphragm.
A semiconductor pressure sensor, wherein a resistance for measuring reverse characteristics of a pn junction between the gauge resistance and the diaphragm and an electrode pad for measurement are formed in a dicing lane of the silicon substrate.