JPH0823107A - Semiconductor device - Google Patents

Abstract

PURPOSE:To provide a semiconductor device having an extremely small chip area by arranging all composite elements on one chip, extremely short and accurate connection between junctions by wiring, and hence extremely small irregularity of the composite elements. CONSTITUTION:Two Schottky barrier diodes are formed on one chip. An epitaxial layer composed of a high-density layer 2 and a low-density layer 3, and an oxide film 4 made of SiO2 are stacked on a semiinsulating Sub layer 1. Two ohmic electrodes 6, 7 and two junctions 8, 9 are formed by Al wiring 5. The ohmic electrodes 6, 7 and the junctions 8, 9 are isolated respectively by an isolation layer 10. The two Schottky barrier diodes are arranged on a semiconductor chip 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly, it is used for a structure of a composite element using a Schottky barrier or a PN junction, and since the elements are formed on one chip, the characteristic deviation between the elements is small. The present invention relates to a technique effectively applied to a semiconductor device which is extremely small and can manufacture devices having uniform characteristics, and which is suitable for manufacturing composite devices in which completely different devices are arranged by changing processes.

[0002]

2. Description of the Related Art For example, a ring connection type mixer using a Schottky barrier, a double balance type mixer, and a composite such as a varicap diode having a uniform C (capacitance) -V (voltage) characteristic curve at a PN junction. In the element, each element is formed for each chip.

As a technique relating to a diode using such a PN junction or Schottky barrier,
For example, "Electronic Components Handbook", published by the Japan Electronic Machinery Manufacturers Association, May 20, 1984, P174-
P211 and the like.

[0004]

However, in the above-mentioned technique, each element is often formed for each chip, and therefore, a composite element is not often formed on one chip and two chips are packaged in one package. However, in addition to variations in characteristics between chips, there are problems such as cost increase and package size increase.

Therefore, it is an object of the present invention to dispose all the composite elements on one chip so that the chip area can be made extremely small, and the connection between the junctions can be made extremely short and accurate by wiring. Therefore, it is an object of the present invention to provide a semiconductor device in which variations in composite elements can be extremely reduced.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0007]

Of the inventions disclosed in the present application, a representative one will be briefly described below.
It is as follows.

That is, the semiconductor device of the present invention is applied to a semiconductor device having a plurality of junctions on one semiconductor chip, and a semi-insulating substrate is provided with a high concentration layer and a high concentration layer for each junction. The low-concentration layer is formed, and the ohmic electrode is taken out from the high-concentration layer corresponding to the cathode side to form a plurality of diodes on one semiconductor chip.

In this case, the junction forming source and process of these diodes are changed to form different types of diodes using Schottky barriers or PN junctions.

In particular, the plurality of diodes are of a ring connection type.

[0011]

According to the above-described semiconductor device, a plurality of diodes are formed on one semiconductor chip, and all the diodes are formed on one chip, for example, a plurality of diodes using a Schottky barrier and a plurality of PN junctions. Since a single diode and a plurality of these types of diodes are arranged, the chip area can be made extremely small.

Further, the connection between chips is not made long by the bonding wire or the like, and the variation in the thickness of the Au wire does not occur. The wiring can be made extremely short and can be made accurately, so that the dispersion of the plurality of diodes can be made extremely small.

That is, in the semiconductor device of the present invention, the same characteristics or different characteristics can be arranged on one chip, and these junctions are solved by three multilayers. That is, the wiring with other joints is usually A on the surface.
However, the present invention has been solved by providing a high-concentration layer as the second layer of the chip.

In the manufacturing process of this semiconductor device, a semi-insulating substrate, a high-concentration layer disposed thereon and a layer for obtaining characteristics are required. This structure has a three-stage epitaxial layer stack. The stacking can be switched by a normal process technique used in the present epitaxial technique, and a normal etching can be performed to lead an ohmic electrode to a high concentration layer.

As a result, the characteristic deviation between the diodes formed on the chip is extremely reduced, and diodes having uniform characteristics can be manufactured. Particularly, the characteristics of the semiconductor device are improved by forming a plurality of diodes into a ring connection type. Further, it is possible to manufacture a semiconductor device in which diodes of different types are arranged by changing the process.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing a main part of a semiconductor device according to an embodiment of the present invention, FIG. 2 is a connection diagram showing a semiconductor device according to the present embodiment, and FIGS. 3 to 9 are semiconductor devices according to the present embodiment. 10 is a cross-sectional view for explaining the manufacturing flow in FIG. 10, FIG. 10 is a schematic configuration diagram when the semiconductor device is of a ring connection type, and FIG. 11 is a cross-sectional view of essential parts showing a modification of the semiconductor device of the present embodiment.

First, the main structure of the semiconductor device of this embodiment will be described with reference to FIG.

In the semiconductor device of this embodiment, for example, two Schottky barrier diodes are formed on one chip, and a high concentration layer 2 and a low concentration layer 3 are formed on a semi-insulating Sub layer (substrate) 1. The epitaxial layer and the oxide film 4 made of SiO ₂ are laminated, two ohmic electrodes 6, 7 and two junctions 8, 9 are formed by the Al wiring 5, and the ohmic electrodes 6, 7 and the junctions 8, 9 are isolated. The semiconductor chip 11 is separated by the layer 10 and has two Schottky barrier diodes.

In this semiconductor device, the ohmic electrodes 6 and 7 are taken out from the high concentration layer 2 corresponding to the cathode side, and for example, as shown in FIG. 2, two Schottky barrier diodes 12 and 13 are connected in series in the forward direction. , The anode electrode of one Schottky barrier diode 12, the cathode electrode of the other Schottky barrier diode 13, the external terminal from the connection point of the cathode electrode of one Schottky barrier diode 12 and the anode electrode of the other Schottky barrier diode 13. Are taken out respectively.

Next, the operation of this embodiment will be described with reference to FIGS. 3 to 9 as an example of a semiconductor device manufacturing flow.

First, Si is formed on the Sub layer 1 by surface oxidation.
An oxide film 14 such as O ₂ is formed. Then, the oxide film 14 and the Sub layer 1 are etched by mesa etching.
In this case, etching is performed so as to leave the oxide film 14 and the Sub layer 1 in the central portion (FIG. 3).

Further, an epitaxial layer of the high concentration layer 2 and an epitaxial layer of the low concentration layer 3 are sequentially formed on the surface after the mesa etching (FIG. 4). Then, a photoresist 15 for etching is applied (FIG. 5).

Then, the high concentration layer 2 and the low concentration layer 3 on the central oxide film 14 are etched and flattened.
After that, an oxide film 16 such as SiO ₂ is formed by CVD, the central portion is etched, and then an N-type impurity such as phosphorus is diffused at a high temperature to isolate the isolation layer 10.
Are formed (FIG. 6).

Subsequently, after etching the oxide film 16 by CVD, the oxide film 4 is formed again by CVD and the portions located at the junctions 8 and 9 are etched. Then, a metal film 17 of tungsten or the like is formed on the portions located at the joints 8 and 9.
Are formed (FIG. 7).

Further, the photoresist 18 is used to etch the portions located at the ohmic electrodes 6 and 7 to a depth reaching the high concentration layer 2 (FIG. 8). Then, after the photoresist 18 is peeled off, electrodes made of Al wiring 5 are drawn at the positions of the ohmic electrodes 6 and 7 and the junctions 8 and 9 (FIG. 9).

As a result, the two Schottky barrier diodes 12 and 13 are connected in series in the forward direction, and the anode electrode of one Schottky barrier diode 12 and the cathode electrode of the other Schottky barrier diode 13,
External terminals can be taken out from the connection points of these Schottky barrier diodes 12 and 13, respectively.

As described above, the structure of this semiconductor device is
It is obtained by a three-stage lamination of the semi-insulating Sub layer 1 and the epitaxial layers arranged on the Sub layer 1. Switching of this lamination can be handled by a normal process technique performed by the present epitaxial technique, Further, in order to guide the ohmic electrodes 6 and 7 to the high concentration layer 2, a usual etching technique can be used.

Next, the operation when current is actually applied will be described.

For example, a signal is applied to the anode electrode of one Schottky barrier diode 12, and the junction 8 acts as the Schottky barrier diode 12. Next, a signal after the action is input to the high concentration layer 2 and is taken out by the ohmic electrode 6 which is the cathode electrode.

Then, the Schottky barrier diode 13 is led to the junction 9 which is the anode electrode of the other Schottky barrier diode 13 and acts as the Schottky barrier diode 13 in the same manner. It is taken out by the ohmic electrode 7 which is the cathode electrode of the barrier diode 13.

Thus, the two Schottky barrier diodes 12 and 13 are connected in series in the forward direction, and the external terminals can be taken out from both ends and the connection point. In addition,
The isolation layer 10 enhances the isolation of the junction between the Schottky barrier diodes 12 and 13.

Therefore, according to the semiconductor device of this embodiment,
Disposing the two Schottky barrier diodes 12, 13 on one semiconductor chip 11 by the high-concentration layer 2, the low-concentration layer 3, and the oxide film 4 stacked on the semi-insulating Sub layer 1. Therefore, the chip area can be made extremely small, and in the connection of the two Schottky barrier diodes 12 and 13, the wiring between the junctions can be made extremely short and the two shots can be accurately formed. The variation of the key barrier diodes 12 and 13 can be made extremely small.

Such a semiconductor device is required, for example, for an element that requires two or more junctions, and two or four matched diodes or double balanced mixers for full-wave rectification are used. It is used for battery backup protection, etc., and it is possible to comply with all conventional specifications in terms of process.

For example, when using for full-wave rectification,
As shown in FIG. 10, by using four diodes in a ring connection type, it is possible to manufacture a semiconductor device using diodes having uniform characteristics with reduced variations in characteristics.

Further, since the characteristic deviation between the diodes can be made extremely small, it is possible to eliminate the problem of impedance matching when viewed from a high frequency.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, with respect to the semiconductor device of this embodiment, the case where the Schottky barrier diodes 12 and 13 using the Schottky barrier are arranged on one semiconductor chip 11 has been described. The present invention is not limited to the example, and as shown in FIG.
It is also widely applicable to a diode having a PN junction formed by the N-type layer 19 and the N-type layer 20.

The present invention is also applicable to a case where a diode using a Schottky barrier and a diode using a PN junction are mixedly formed on one semiconductor chip.
For example, a Schottky barrier diode, a Pin diode, a switching diode, a varicap diode, a Zener diode, and the like can be combined as desired, and a plurality of different types of diodes can be formed by changing the junction forming source and process.

Further, in the above embodiment, the isolation layer 1 is formed by diffusing N-type impurities at high temperature.
Although the case of forming 0 has been described, the present invention is also applicable to the case of forming by implantation of N-type ions and the manufacturing process of this semiconductor device is not limited in any way.

[0041]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1). A high-concentration layer and a low-concentration layer are formed on each of a plurality of junctions on a semi-insulating substrate, and an ohmic electrode is taken out from the high-concentration layer corresponding to the cathode side. Since the diode can be formed on one semiconductor chip, the chip area can be made extremely small.

(2) Due to the above (1), the connection between the plurality of diodes can be made extremely short and accurately by wiring such as Al, so that the variation between the plurality of diodes can be made extremely small. It becomes possible.

(3) In the above (1), even when different types of diodes are formed, a plurality of types of diodes using a Schottky barrier or a PN junction can be easily formed by changing the diode junction formation source and process. It is possible to form

(4) In the above item (1), since the plurality of diodes are of the ring connection type, the characteristic deviation between the diodes can be extremely reduced, so that the characteristics of the semiconductor device can be improved. .

(5) Due to the above (1) to (4), it is possible to improve the effective area of the chip, reduce the characteristic variations due to the miniaturization and miniaturization of the element, and eliminate the problem of impedance matching when viewed at high frequencies. It is possible to obtain a semiconductor device that can expect the effect.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a connection diagram showing a semiconductor device of this embodiment.

FIG. 3 is a cross-sectional view showing the manufacturing flow of the semiconductor device of this embodiment.

FIG. 4 is a cross-sectional view showing the manufacturing flow (continued from FIG. 3) in the semiconductor device of this embodiment.

FIG. 5 is a cross-sectional view showing the manufacturing flow (continued from FIG. 4) in the semiconductor device of this embodiment.

FIG. 6 is a cross-sectional view showing the manufacturing flow (continued from FIG. 5) in the semiconductor device of this embodiment.

FIG. 7 is a cross-sectional view showing the manufacturing flow (continued from FIG. 6) in the semiconductor device of the present embodiment.

FIG. 8 is a cross-sectional view showing the manufacturing flow (continued from FIG. 7) in the semiconductor device of this embodiment.

FIG. 9 is a cross-sectional view showing the manufacturing flow (continued from FIG. 8) in the semiconductor device of the present embodiment.

FIG. 10 is a schematic configuration diagram in the case where the semiconductor device of this embodiment is of a ring connection type.

FIG. 11 is a main-portion cross-sectional view showing a modification of the semiconductor device of this embodiment.

[Explanation of symbols]

 1 Sub layer (substrate) 2 High concentration layer 3 Low concentration layer 4 Oxide film 5 Al wiring 6,7 Ohmic electrode 8,9 Junction 10 Isolation layer 11 Semiconductor chip 12,13 Schottky barrier diode 14 Oxide film 15 Photoresist 16 Oxide film 17 Metal film 18 Photoresist 19 P-type layer 20 N-type layer

Claims (3)

[Claims] 1. A semiconductor device having a plurality of junctions on one semiconductor chip, wherein a high concentration layer and a low concentration layer are formed on each of the plurality of junctions on a semi-insulating substrate, and a cathode is formed. A semiconductor device, wherein an ohmic electrode is taken out from the high concentration layer corresponding to a side, and a plurality of diodes are formed on one semiconductor chip. 2. When forming the plurality of diodes, a plurality of different types of diodes using a Schottky barrier or a PN junction are formed by changing a junction forming source and a process of the diode. The semiconductor device according to claim 1. 3. The semiconductor device according to claim 1, wherein the plurality of diodes are of a ring connection type.