JP2000031500A - High frequency semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a superior high frequency semiconductor device having a constitution capable of accurately measuring the high frequency characteristics, such as input and output impedances, etc., at chip ends, without assembling. SOLUTION: An FET 3, a signal input stripline for inputting signals to the FET 3 and a signal output stripline for outputting signals to the outside are formed on one main plane of a compd. semiconductor substrate 4, and high frequency measuring surface ground electrodes 5, respectively formed near the signal input end of the signal input strip line and near the signal output end of the signal output strip line and a back side electrode 8 formed on the other main plane of the compd. semiconductor substrate 4 are electrically connected via V-grooves 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a high-frequency semiconductor device in which an FET and a strip line are integrally formed on a semiconductor substrate such as GaAs.

[0002]

2. Description of the Related Art At a high frequency of 10 GHz or more, a strip line can be formed compactly by using a semi-insulating GaAs substrate as a dielectric material. Is not so large, and the impedance of the input and output can be increased to 50Ω by the impedance matching circuit constituted by the strip line, so that a high-frequency circuit with less loss can be constituted.

In this type of high-frequency semiconductor device in which an FET and a strip line are integrally formed on a semi-insulating GaAs substrate, the strip line is formed on the surface and has a constant width for obtaining a predetermined characteristic impedance and a back electrode. It is composed of Therefore, when measuring the high-frequency characteristics of a chip in which an FET and a strip line are integrally formed on a semi-insulating GaAs substrate, it is necessary to always use the strip line located on the front surface and the back electrode on the back surface of the chip.

However, in this type of conventional chip, only the input side strip line and the output side strip line are provided on the chip surface, and grounded electrodes are formed on both sides or one side of the input end and output end strip lines. It is extremely difficult to measure the input / output impedance at the chip end because it is not performed.As for the measurement of the input / output impedance, it is measured after assembling it in a package etc., and the measurement error is large and the reliability is insufficient. It has been extremely difficult to accurately measure the impedance at the end of the chip.

FIG. 2 shows a conventional high frequency semiconductor device in which an FET and a strip line are integrally formed on a semi-insulating GaAs substrate. 2, the input side matching circuit 1 is connected to the gate terminal G, the output side matching circuit 2 is connected to the drain terminal D, and the input and output impedance of the FET 3 is set to 50Ω.
It works to keep the loss due to impedance mismatch small. The input side matching circuit 1 and the output side matching circuit 2 are on the main surface side of the semi-insulating GaAs substrate 4,
The semi-insulating GaAs substrate 4 is made of a dielectric material, and a strip line is formed between the semi-insulating GaAs substrate and a back electrode formed on the back surface of the semi-insulating GaAs substrate (not shown in FIG. 2).

[0006] The input signal enters the chip end of the input side matching circuit 1, is amplified by the FET 3, passes through the output side matching circuit 2, and is drawn out from the end. Terminal S is
This is the source terminal of FET3 connected to the back electrode using the V groove.

[0007]

In the conventional high-frequency semiconductor device shown in FIG. 2, when measuring the high-frequency characteristics of a chip, the chip is actually assembled in a package or the like, and the input and output ends of the chip are bonded with bonding wires. The measurement is possible only by connecting. Therefore, it has been extremely difficult to evaluate high-frequency characteristics before assembling into a package, that is, in a wafer state or a chip state.

In addition, the high frequency performance such as input / output impedance when assembled into a package using bonding wires or the like has a very large error. When an external impedance matching circuit is designed to completely reduce the impedance to 50Ω. This causes a large error and causes impedance mismatch.

The present invention has been made in view of the above points, and provides an excellent high-frequency semiconductor device having a configuration capable of accurately measuring high-frequency characteristics such as input and output impedances of a chip end without assembling. It is intended to be.

[0010]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a high frequency semiconductor device in which an FET and a strip line are integrally formed on the main surface of the same compound semiconductor substrate. High-frequency characteristics electrically connected to both sides or one side of the input end of the strip line and both sides or one side of the output end of the output side of the strip line via holes to the back electrode formed on the opposite main surface side of the substrate. Place a surface electrode for measurement. Then, high-frequency characteristics are measured using a high-frequency prober for the surface electrode.

Here, at least a part of the surface electrode is formed on a flat portion of the compound semiconductor substrate, or is arranged at a distance from the strip line so as not to affect the high frequency characteristics. I have.

According to the present invention, it is possible to measure high-frequency characteristics such as input / output impedance in a wafer state or a chip state without errors without assembling a chip on a package using bonding wires.

When a matching circuit is provided outside the chip, the impedance at the end of the chip can be accurately measured, so that a perfect matching of 50Ω can be achieved.

[0014]

FIG. 1 is a plan view and a sectional view showing an embodiment of a high-frequency semiconductor device according to the present invention. 1, components equivalent to those in FIG. 2 are denoted by the same reference numerals and symbols.

One embodiment of the present invention shown in FIG.
On the main surface of the semi-insulating GaAs substrate 4, an input-side matching circuit 1
And an output-side matching circuit 2 are integrally formed on the input and output sides of the FET 3, and a surface ground electrode 5 is provided on both sides of the signal input end of the signal input strip line and the signal output end of the signal output strip line. Are located. The front ground electrode 5 is electrically connected to the back electrode via the V groove 6. The surface ground electrode 5 is formed from the V groove 6 to the flat part of the semi-insulating GaAs substrate 4.

FIG. 1B is a sectional view taken along the line AA 'in FIG. 1A. In FIG. 1B, the strip line surface electrode 7 is located at the center of the surface ground electrode 5,
Front ground electrode 5 is electrically connected to strip line back electrode 8 via V groove 6. Therefore, when measuring the impedance of the input terminal and the output terminal of the chip, without assembling the chip using bonding wires,
In a wafer state or a chip state, measurement can be performed from the front side using a high-frequency prober or the like. Further, since the input / output impedance at the end of the chip can be accurately measured, the design becomes very easy even when an external matching circuit is provided.

If the distance between the surface ground electrode 5 and the strip line surface electrode 7 is about 30 μm, there is no effect on high frequency. The present invention is applicable to compound semiconductors other than GaAs.

[0018]

As described above, according to the present invention, the following effects can be obtained.

(1) Since the front ground electrode connected to the back electrode is arranged at the input terminal and the output terminal of the chip,
Without assembling using bonding wires, it is possible to measure high-frequency characteristics such as the impedance of the input and output terminals from the substrate surface side using a high-frequency prober or the like from the surface side in the wafer state or chip state. It becomes possible.

(2) Since the impedances at the input terminal and the output terminal of the chip can be accurately measured, it is easy to design a matching circuit outside the chip.

[Brief description of the drawings]

FIG. 1A is a plan view showing an embodiment of a high-frequency semiconductor device according to the present invention. FIG. 1B is a cross-sectional view taken along line AA ′ in the plan view of FIG.

FIG. 2 is a plan view showing a conventional high-frequency semiconductor device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Input side matching circuit 2 Output side matching circuit 3 FET 4 Semi-insulating GaAs substrate 5 Surface ground electrode 6 V groove 7 Strip line surface electrode 8 Strip line back surface electrode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01P 5/08

Claims (8)

[Claims] 1. An FET, a signal input stripline for inputting a signal to the FET, and a signal output stripline for leading a signal from the FET to the outside are formed on one main surface of the compound semiconductor substrate. A surface electrode for high-frequency measurement formed near the signal input end of the signal input strip line and near the signal output end of the signal output strip line, and on the other main surface of the compound semiconductor substrate. A high-frequency semiconductor device in which the formed back electrode is electrically connected to the compound semiconductor substrate via a hole formed in the compound semiconductor substrate. 2. A compound semiconductor substrate, an FET and a signal input strip line and a signal output strip line formed on one main surface side of the compound semiconductor substrate,
In the vicinity of the signal input end of the signal input strip line, and near the signal output end of the signal output strip line, a surface electrode for high frequency measurement, and on the other main surface side of the compound semiconductor substrate A high-frequency semiconductor device comprising: a back electrode formed; wherein the front electrode and the back electrode are electrically connected to each other through a hole formed in the compound semiconductor substrate. 3. An FET, a signal input strip line, and a signal output strip line are integrally formed on a compound semiconductor substrate, and at least one of a signal input end of the signal input strip line and the signal output strip line. A high-frequency wave having a surface electrode for high-frequency measurement formed on at least one side of the signal output end of the strip line and a back electrode formed on the opposite main surface side of the compound semiconductor substrate and electrically connected through a hole. Semiconductor device. 4. The device according to claim 1, wherein two surface electrodes are formed so as to sandwich the signal input strip line, and the other two surface electrodes are formed so as to sandwich the signal output strip line. 3. The high-frequency semiconductor device according to any one of 3. 5. The high-frequency semiconductor device according to claim 1, wherein a part of said surface electrode is formed on a flat portion of said compound semiconductor substrate. 6. The high-frequency semiconductor device according to claim 1, wherein said hole has a V-shape, and said front surface electrode and said back surface electrode are directly connected. 7. The device according to claim 1, wherein the surface electrode is formed at a distance from the signal input strip line or the signal output strip line so as not to affect high frequency characteristics. The high-frequency semiconductor device according to any one of the above. 8. The signal processing apparatus according to claim 1, wherein the surface electrode and the signal input strip line, or the surface electrode and the signal output strip line are formed at a distance of 30 μm or more. A high-frequency semiconductor device according to any one of the above.