JPH08130222A - High-output semiconductor device - Google Patents

Abstract

PURPOSE: To uniformly operate each HBT on a chip, and improve gain,and power efficiency, by making the longitudinal directions of emitters of a plurality of transistors radial, and arranging the transistors on a closed loop, at nearly equal intervals. CONSTITUTION: HBT's constituted of base electrodes 6, emitter electrodes 8 and collector electrodes 7 are arranged at a plurality of positions on a circumference. Each of the emitter electrodes 8 is connected with an emitter pad 4 arranged inside the circumference. The distance between the electrode 8 and the pad 4 is set almost constant. The emitter pad 4 is connected with ground conductor formed on the back, through a viahole 9 penetrating a semi-insulating GaAs substrate 1. The base electrode 6 of each of the HBT's is electrically connected with a base pad 2 through a base electrode wiring 6a outside the circumference. The collector electrode 7 is electrically connected with a collector pad 3 through a collector wiring 7a. Thereby electric uniformity in the HBT's can be ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-output semiconductor device,
In particular, the present invention relates to a semiconductor device in which a plurality of transistors are connected in parallel to achieve high output.

[0002]

2. Description of the Related Art The demand for high-frequency and high-power semiconductor devices has greatly increased with the development of communication equipment. In particular, in information terminal mobile devices typified by car phones, mobile phones, and the like, a high-power semiconductor device that operates with high efficiency is required because battery-powered high-power operation and long-term communication are performed. That is, there is a demand for a high-output semiconductor device that minimizes power loss inside the semiconductor device and efficiently converts the applied DC power into high-frequency power.

A field effect transistor using a GaAs semiconductor has been put into practical use and mass-produced as a high-output semiconductor device satisfying such demands. HBT) has attracted attention as a high-output semiconductor device because of its excellent high-frequency characteristics and high current driving capability.

In such a high-output semiconductor device, in order to handle high-frequency high power, a plurality of transistors are arranged on a semiconductor substrate, and these transistors are connected to each other in parallel to achieve high output.

For example, Japanese Patent Application Laid-Open No. 5-315352 discloses that the wiring distance from each transistor cell to the ground pad is greatly reduced and equalized without increasing the chip size, and at the same time, each transistor is connected from the input pad to each transistor. As shown in FIG. 2, for the purpose of equalizing the electrical length from the cell to the output pad in any transistor cell and improving the gain of the transistor at high frequencies, as shown in FIG.
A high-output semiconductor device in which a plurality of HBTs are arranged on a substrate has been proposed.

Referring to FIG. 2, a plurality of HBTs are arranged in a line in a transistor region 15, and a base electrode 16, a collector electrode 17, and an emitter electrode 1 of each HBT are provided.
8 are connected to each other and each of the base pads 1
2, the collector pad 13 and the emitter pad 14.

The base pad 12 is arranged on an extension line in the direction in which the transistor cells are arranged, a collector pad 13 is arranged on the opposite side of the base pad across the transistor cell, and a straight line connecting the base pad 12 and the collector pad 13 is formed. An emitter pad 14 is formed in the vicinity of the transistor cell in the direction perpendicular to the.

The emitter pad 14 is used as a ground terminal, the base pad 12 is used as an input terminal, and the collector pad 13 is used as an output terminal for connection to an external circuit.

[0009]

However, in such a configuration in which a plurality of HBTs are arranged in a line on the chip, a part of the DC power supplied as a power supply through the base pad 12 and the collector pad 13 or a signal When a part of the high frequency power is converted into heat as power loss, the temperature rise of the HBT near the center of the array becomes larger than that of the peripheral HBT due to thermal interference of the adjacent HBT.

Along with this, the collector current concentrates on the HBT near the center, the temperature rises more and more, and the heat concentrates on the HBT near the center.

As a result, uniform operation of all HBTs cannot be performed, resulting in a decrease in gain and a decrease in power efficiency. In some cases, such a series of thermal runaways may cause deterioration or destruction of the element.

By the way, in order to make each HBT operate uniformly, a means for preventing thermal runaway and equalizing the temperature by inserting a ballast resistor between the emitter electrode of each HBT and the ground is used. This impairs the high-frequency characteristics of the transistor, and is not advantageous for use in a high-frequency region.

Further, the number of manufacturing processes for producing a ballast resistor increases.

Further, a method of reducing the thermal interference of the elements by increasing the arrangement intervals of the HBTs can be adopted, but an increase in chip area is unavoidable due to an increase in chip area.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to allow a plurality of HBTs to operate uniformly on a chip,
It is an object of the present invention to provide a high-output semiconductor device in which the gain and the power efficiency are improved.

[0016]

In order to achieve the above object, a high-power semiconductor device according to the present invention performs a high-output operation by connecting a plurality of transistors arranged on a semiconductor substrate in parallel with each other. The longitudinal direction of the emitters of the plurality of transistors is radial, and the plurality of transistors are arranged at substantially equal intervals on a predetermined closed curve, and the electrical ground point of each transistor is disposed inside the predetermined closed curve. It is characterized by the following.

Further, in the high-power semiconductor device according to the present invention, the electrical ground point is connected to a ground conductor on the back surface of the semiconductor substrate via a via hole penetrating the semiconductor substrate. I do.

In the high-power semiconductor device according to the present invention, preferably, the predetermined closed curve is a circle, and the electric ground point is arranged at a substantially central portion of the circle. .

[0019]

According to the present invention, since all the emitter electrodes are adjacent to each other at equal intervals, heat generation and thermal interference of each HBT cause
Concentration of heat on a particular HBT is avoided.

Further, according to the present invention, since the wiring distances from the electrical ground point to each emitter electrode can be all equal, the parasitic elements (resistance, inductance, capacitance) in the wiring portion are also equal, and each transistor can be made uniform. Can work.

Further, according to the present invention, an emitter electrode,
The fact that the heat radiation paths to the back surface of the chip of each transistor through the emitter pad and the via hole are exactly the same also contributes to the uniform heat distribution. Therefore, according to the present invention, all the transistors on all the chips can be uniformly operated both electrically and thermally.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings according to embodiments.

FIG. 1 is a plan view of a high-power semiconductor device using an AlGaAs / GaAs HBT as a transistor according to one embodiment of the present invention.

Referring to FIG. 1, a plurality of HBTs each comprising a base electrode 6, an emitter electrode 7, and a collector electrode 8 are arranged at regular intervals on the circumference of a predetermined circle. Each of the emitter electrodes 7 is connected to an emitter pad 4 arranged inside the circumference where the HBTs are arranged. The distance between the emitter electrode 7 and the emitter pad 4 is set substantially equal.

The emitter pad 4 is made of semi-insulating Ga.
Through the via hole 9 penetrating the As substrate 1, GaA
The substrate 1 is connected to a ground conductor (not shown) provided on the back surface of the substrate 1.

Further, the base electrode 6 of each HBT is
Are electrically connected to the base pad 2 through the base electrode wiring 6a outside the circumference on which is disposed. Collector electrode 7 is electrically connected to collector pad 3 through collector electrode 7a.

In the pattern arrangement of this embodiment, when mounted on a chip carrier, the emitter pad 4 is electrically grounded through the ground conductor on the back surface, and the base pad 2 and the collector pad 3 are respectively connected by wire bonding or the like. Functions as an input terminal and an output terminal.

According to the present embodiment, since the wiring distances from the electrical ground point to each emitter electrode 8 can be all equal among a plurality of HBTs, the parasitic elements (resistance, inductance, and capacitance) in the wiring portion are also equal, Electrical uniformity among the HBTs can be ensured. In addition, each HBT
Is radiated from the back surface of the substrate via the emitter electrode 8, the emitter pad 4, the via hole 9, and the like.
Thermal uniformity of T is ensured, and therefore, all HBTs on the chip can be operated uniformly, and gain and power efficiency are improved.

Further, according to the present embodiment, the emitter electrode 8
Are arranged so as to be adjacent to each other at equal intervals, current concentration and heat concentration do not occur in a specific HBT.
Deterioration and destruction of HBT characteristics are avoided, and high reliability and high yield are achieved.

Although the present invention has been described with reference to the above embodiment, the present invention is not limited to the above embodiment but includes various embodiments according to the principle of the present invention. For example, in the above-described embodiment, the configuration in which the HBTs are arranged on a perfect circle is shown. However, even when the HBTs are arranged on an ellipse, the same effect is achieved when the HBTs are arranged at equal intervals. I do.

[0031]

The present invention as described above (Claim 1)
According to, all the emitter electrodes are adjacent to each other at equal intervals,
This has an effect that heat is prevented from being concentrated on a specific transistor due to heat dissipation of each transistor.

Further, according to the present invention (claim 1), since the wiring distances from the electrical ground point to the respective emitter electrodes can be made equal, the parasitic elements (resistance, inductance, capacitance) in the wiring portion also become equal. , Each transistor can maintain electrical uniformity.

Further, according to the present invention (claim 2), heat generated from the transistor is radiated from the back surface of the substrate via the emitter electrode, the emitter pad, the via hole, and the like. , The temperature uniformity of each transistor is maintained.

As described above, according to the present invention (claims 1 and 2), all the transistors on the chip can be operated uniformly, and the gain and the power efficiency can be improved.

According to the present invention (claims 1 and 2),
Since current concentration and heat concentration do not occur in a specific transistor, deterioration and destruction of characteristics of the transistor due to the current concentration and heat concentration can be avoided, and high reliability and high yield can be achieved.

Preferably, the present invention (claim 3)
The same effects can be achieved in the same manner as described above.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration of an embodiment of a high-power semiconductor device of the present invention.

FIG. 2 is a plan view showing an arrangement of conventional high-power semiconductor transistors.

[Explanation of symbols]

 1, 11 GaAs substrate 2, 12 base pad 3, 13 collector pad 4, 14 emitter pad 15 transistor region 6, 16 base electrode 6a base electrode wiring 7, 17 collector electrode 7a collector electrode wiring 8, 18 emitter electrode 9 via hole

Claims (3)

[Claims] 1. In a semiconductor device for performing a high output operation by connecting a plurality of transistors arranged on a semiconductor substrate in parallel to each other, the emitters of the plurality of transistors have a radial direction in which a predetermined closed curve is formed. A high output semiconductor device, wherein the plurality of transistors are arranged at substantially equal intervals, and an electric ground point of each transistor is arranged inside the predetermined closed curve. 2. The electric ground point is connected to a ground conductor on the back surface of the semiconductor substrate via a via hole penetrating the semiconductor substrate. High power semiconductor device. 3. The high-power semiconductor device according to claim 1, wherein the predetermined closed curve is a circle, and the electrical ground point is arranged substantially at the center of the circle.