JPS60251672A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To facilitate manufacture by each constituting semiconductor active layers for enhancement type and depletion type Schottky junction type field- effect transistors by the layer section of a semiconductor active layer common in these active layers. CONSTITUTION:A semiconductor active layer 23 is formed into a semiconductor substrate 1 in uniform thickness through the implantation treatment of impurity ions, and a source electrode 6 and a drain electrode 7 are shaped onto the layer section 24 of the semiconductor active layer 23 so as to be in ohmic-contact while a source electrode 16 and a drain electrode 17 are formed onto a layer section 25 so as to be in ohmic-contact. A gate electrode 5 consisting of a material containing molybdenum, silicon and nitrogen is shaped onto the layer section 24 so as to form a Schottky junction 4. A gate electrode 15 composed of a material having a composition ratio different from the gate electrode 5 is formed onto the layer section 25 so as to shape a Schottky junction 14. Accordingly, a semiconductor device can be manufactured easily by a simple process having a function as an inverter.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention Invention 1 A semiconductor device having an enhancement type Schottky junction field effect transistor and a depletion type Schottky junction field effect transistor;
and its manufacturing method.

Background of the Invention As a semiconductor device having an enhancement type Schottky junction field effect transistor and a depletion type Schottky junction field effect transistor, a semiconductor device having the configuration described below with reference to FIG. 1 has been proposed. has been done.

That is, an enhancement type Schottky junction field effect transistor ET and a depletion type Schottky junction field effect transistor DT are manufactured by using a semi-insulating, P type or N type semiconductor substrate 1 made of, for example, Qa or As. is configured.

In the Schottky junction field effect transistor ET, impurity ions are added into the semiconductor substrate 1 from the main surface 2 side to provide P-type or N-type impurity ions when the semiconductor substrate 1 has semi-insulating properties; In the case of N type, the semiconductor active layer 3 is formed by implanting impurity ions that give a conductivity type opposite to that of the semiconductor substrate.

Furthermore, the Schottky junction field effect transistor ET is
A gate electrode 5 is attached to the semiconductor active layer 3 so as to form a Schottky junction 4, and a source electrode 6 is ohmically attached to the semiconductor active layer 3 at a position sandwiching the gate electrode 5. and a drain electrode 7.

On the other hand, the Schottky junction field effect transistor DT is
A semiconductor active layer 3 is formed in the semiconductor substrate 1 from the main surface 2 side.
It has a semiconductor active layer 13 formed similarly.

In this case, the semiconductor active layer 13 has the same thickness as the semiconductor active layer 3 but has a higher carrier concentration than the semiconductor active layer 3, or as shown in the figure, the semiconductor active layer 13 has the same thickness as the semiconductor active layer 3 but has a higher carrier concentration than the semiconductor active layer 3. Although having the same carrier concentration, the semiconductor active layer 3
It has a thicker thickness than the . Further, the semiconductor active layers 3 and 13 are connected to each other.

Further, the Schottky junction field effect transistor DT includes a gate electrode 15 attached on the semiconductor active layer 4 to form a Schottky junction 14, and a position on the semiconductor active layer 13 sandwiching the gate electrode 15. A source electrode 16 and a drain electrode 17 each ohmically attached.
and has. In this case, the gate electrode 15 is formed of the same material as the gate electrode 5 of the Schottky junction field effect transistor ET described above. In addition, the source electrode 16
and the Schottky junction field effect transistor E mentioned above.
The drain electrode 7 of T is formed by the part of the electrode 18 on the side of the semiconductor active layers 13 and 3 that is common to the source electrodes 16 and 7 and extends across the connection position of the semiconductor active layers 3 and 13.

The above is the configuration of a conventionally proposed semiconductor device including an enhancement type Schottky junction field effect transistor and a depletion type Schottky junction field effect transistor.

According to such a configuration, in the enhancement type Schottky junction field effect transistor ET, when a control voltage is not applied between the gate electrode 5 and the source electrode 6, the Schottky junction 4 spreads toward the semiconductor active layer 3 side. A depletion layer 9 is formed therein, and the depletion layer 9 reaches the semiconductor substrate 1 as shown in the figure.

Therefore, in such a state, even if a required power source is connected between the source electrode 6 and the drain electrode 7, the current flowing through the semiconductor active layer 3 to the outside through the source electrode 6 and the drain electrode 7 cannot be obtained. I can't do it.

However, if a control voltage with the required polarity is applied between the gate electrode 5 and the source electrode 6 from this state, the voltage will spread within the semiconductor active layer 3 until it reaches the semiconductor substrate 1. The depletion layer 9, which had been in contact with the depletion layer 9, retreats toward the Schottky junction 4 by an amount corresponding to the value of the control voltage.

Therefore, at this time, the source electrode 6 and the drain electrode 7
If a required power source is connected between them, a current flows in the semiconductor active layer 3 to the outside through the source electrode 6 and the drain electrode 7 at a value corresponding to the control voltage.

Furthermore, in the depletion type Schottky junction field effect transistor DT, even when no control voltage is applied between the gate electrode 15 and the source electrode 16, a control voltage is applied between the gate electrodes 15 and 16 with the required polarity. Even in this state, a depletion layer 19 is formed that extends from the Schottky junction 14 to the semiconductor active layer 13 side.
This has not been achieved. For this reason, the source electrode 16
If a necessary power supply is connected between the source electrode 16 and the drain electrode 17 in the semiconductor active layer 13,
A current is obtained that flows to the outside through it.

Therefore, according to the conventional semiconductor device shown in FIG. 1, the gate electrode 1 of the Schottky junction field effect transistor DT is
5 to the source electrode 16 of the Schottky junction field effect transistor DT, and also between the 1 north electrode 6 of the Schottky junction field effect transistor ET and the drain electrode 17 of the Schottky junction field effect transistor DT. If a control voltage is applied between the gate electrode 5 and the source electrode 6 of the Schottky junction field effect transistor ET, the train electrode 7 of the Schottky junction field effect transistor ET and the Schottky An output voltage corresponding to the control voltage is obtained between the source electrode 16 of the junction field effect transistor DT and the source electrode 6 of the Schottky junction field effect transistor ET. Therefore, it is possible to obtain a function as an inverter using the Schottky junction field effect transistor ET as a drive transistor and the Schottky junction field effect transistor DT as a load.

In this way, according to the conventional semiconductor device shown in FIG.
The function as an inverter can be obtained, but for this purpose, the semiconductor substrates 1 have the same thickness but different carrier concentrations, or have the same carrier concentration but mutually different carrier concentrations. Two carrier concentrations with increasing thickness 3
and 13 need to be formed. Therefore, it has the disadvantage that many steps are required to manufacture the semiconductor device.

Book B (Di) Accordingly, the present invention aims to propose a novel semiconductor device and a method for manufacturing the same that are free from the above-mentioned drawbacks.

The semiconductor device according to the first invention of the present application has the following configuration similar to the conventional semiconductor device described above in FIG.

That is, a first semiconductor active layer formed on a substrate;
a first gate electrode disposed on the first semi-integral active layer to form a first Schottky junction; and a first semiconductor active layer at positions sandwiching the first gate electrode. , a first enhancement-type Schottky junction field effect transistor having a first source electrode and a first train electrode, each of which is ohmically attached.

Further, a second semiconductor active layer formed on the above-described substrate, a second gate electrode attached to form a second Schottky junction on the second semiconductor active layer, and a second semiconductor active layer formed on the substrate described above; a depletion-type second Schottky junction field-effect transistor having a second source electrode and a second drain electrode that are ohmically impeded at positions sandwiching a second gate electrode on the semiconductor active layer; has.

However, the semiconductor device according to the first invention of the present application has the following configuration in the semiconductor device having the above-described configuration.

That is, the first and second semiconductor active layers are first and second steps of the semiconductor active layer common thereto.

Further, the first gate electrode is formed of a first material that forms a first Schottky barrier by a first Schottky junction between the first gate electrode and the first step serving as the first semiconductor active layer,
On the other hand, the second gate electrode is connected to the first layer as a second semiconductor active layer by a second Schottky junction.
The second material forms a second Schottky barrier that is lower than the Schottky barrier of the second Schottky barrier. In this case, the second material of the second gate electrode contains the same elements as the first material of the first gate electrode, but has a different composition ratio.

The above is the configuration of the semiconductor device according to the first invention of the present application.

According to the semiconductor device according to the first invention of the present application having such a configuration, the first semiconductor active layer for an enhancement type Schottky junction field effect transistor and the second semiconductor active layer for a depletion type Schottky junction field effect transistor are provided. Since the semiconductor active layers of the semiconductor active layers are composed of the first and second frame portions of the semiconductor active layers common to them, the two semiconductor active layers are respectively disposed on the substrate as in the conventional semiconductor device described above in FIG. There is no need to form it separately.

Further, according to the semiconductor device according to the first invention of the present application,
A first gate electrode for an enhancement type Schottky junction field effect transistor and a second gate electrode for a depletion type Schottky junction field effect transistor each contain the same element but have different composition ratios. However, since the first and second gate electrodes contain the same element and only have different dimensional composition ratios, gate electrodes can be easily formed.

Therefore, the semiconductor device according to the first invention of the present application has the feature that the semiconductor device can be manufactured more easily than the conventional semiconductor device described above in FIG.

Further, the method for manufacturing a semiconductor device according to the second invention of the present application is as follows:
A semiconductor device according to the first invention of the present application is manufactured by taking the steps described below.

That is, a step is taken in which a semiconductor active layer is formed on a substrate to have a uniform thickness at each portion.

Next, a first gate electrode made of a first material is placed on the first peripheral portion of the semiconductor active layer, and a first Schottky junction is formed between the first gate electrode and the first forehead portion to form a first Schottky barrier. After or before forming the first goo 1~electrode, the second peripheral part of the semiconductor active layer contains the same element as the first material so as to form the first material. a second gate electrode made of a second material having a different composition ratio;
A forming step is taken to form a second Schottky junction that forms a second Schottky barrier lower than the first Schottky barrier between the forehead and the forehead.

Further, after forming either one or both of the first and second gate electrodes, the IC is provided with a first gate electrode on the first peripheral portion of the semiconductor active layer at a position sandwiching the first gate electrode. At the same time, a second gate electrode is sandwiched on a second circumferential portion of the semiconductor active layer. The second source electrode and the first drain electrode are formed in ohmic contact with the second forehead portion at the position where the second source electrode and the first drain electrode are formed.

The above is the method for manufacturing a semiconductor device according to the second invention of the present application.

According to the method for manufacturing a semiconductor device according to the second aspect of the present invention, the steps of forming a semiconductor active layer on a substrate and forming a first gate electrode on a first peripheral portion of the semiconductor active layer are provided. forming a second gate electrode on a second peripheral portion of the semiconductor active layer;
A very simple process including forming a first source electrode, a first drain electrode, a second source electrode, and a second train electrode, respectively, on the circumferential portion of the.

Moreover, in the step of forming the first and second electrodes, the second gate electrode is formed of a material that contains the same element as the first gate electrode and has a composition ratio that is mutually exclusive. Since the steps are slightly different, the semiconductor device according to the first invention of the present application can be manufactured simply, easily, and with good reproducibility.

First, an embodiment of a semiconductor device according to the first invention of the present application will be described with reference to FIG.

In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

The embodiment of the semiconductor device according to the first invention of the present application shown in FIG. 2 has the same structure as the conventional semiconductor device shown in FIG. 1 except for the following points in the structure described above in FIG.

That is, the semiconductor active layers N3 and 13 are formed in the semiconductor substrate 1 from the main surface 2 side by impurity ions, as in the case where the semiconductor active layers 3 and 13 of the conventional semiconductor device described above in FIG. 1 are formed. The frame portions 24 and 25 of the semiconductor active layer 23 that are common to the semiconductor active layers 3 and 13 are formed.

Further, the gate electrode 5 of the enhancement type Schottky junction field effect transistor ET contains molydodene, silicon, and nitrogen that form a Schottky barrier by the Schottky junction 4 between the gate electrode 5 and the peripheral portion 24 as the semiconductor active layer 3. The Schottky barrier formed by the Schottky junction 4 is formed to have a height of 0.9 to 1.0V.

Further, the gate electrode 15 of the depletion type Schottky junction field effect transistor ET is connected to the semiconductor active layer 13.
1. The Schottky junction 14 is made of a material that forms a lower Schottky barrier than the Schottky barrier caused by the Schottky junction 4 described above. In this case, the material of the gate electrode 15 is
It has a composition ratio different from that of the material of the gate electrode 5, in that it contains molybdenum, silicon, and nitrogen, which are the same elements as the material of the gate electrode 5, or it contains only a small amount of nitrogen compared to the material of the gate electrode 5. , Therefore, the Schottky barrier due to the Schottky junction 14 is formed to have a height of 0.45-0.55V.

Further, a source electrode 6 and a drain electrode 7 of an enhancement type Schottky junction field effect transistor ET are ohmically attached to a peripheral portion 24 of a semiconductor active layer 23 as a semiconductor active layer 3, and a depletion type Schottky A source electrode 16 and a drain electrode 17 of the junction field effect transistor ET are ohmically attached to the peripheral portion 25 of the semiconductor active layer 23 as the semiconductor active layer 13 .

The above is the configuration of the embodiment of the semiconductor device according to the first invention of the present application.

According to this configuration, except for the matters mentioned above, it has the same configuration as the conventional semiconductor device described above in FIG. 1, so a detailed explanation will be omitted. It can also function as an inverter.

However, according to the semiconductor device according to the first invention of the present application shown in FIG. 2, the semiconductor active layer 3 of the enhancement type Schottky junction field effect transistor ET,
Since the semiconductor active layer 13 of the depletion type Schottky junction field effect transistor DT consists of the peripheral parts 24 and 25 of the semiconductor active layer 23 common to them, the semiconductor active layers 3 and 13 can be easily formed. .

In addition, the gate electrode 5 of the enhancement type Schottky junction field effect transistor ET and the gate electrode 5 of the depletion type Schottky junction field effect transistor ET
Since the electrodes 15 and 15 contain the same elements and only have different composition ratios, the gate electrodes 5 and 15 can be easily formed.

Therefore, the semiconductor device according to the first invention of the present application shown in FIG. 2 has the characteristic that the semiconductor device can be formed more easily than in the case of FIG.

Next, an embodiment of the method for manufacturing a semiconductor device according to the second invention of the present application will be described with reference to FIGS. Let me explain the case.

In FIGS. 3A to 3D, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

A method for manufacturing a semiconductor device according to the second invention of the present application shown in FIGS. 3A to 3D involves the following sequential steps to manufacture the semiconductor device according to the first invention of the application shown in FIG.

That is, the semiconductor substrate 1 is prepared in advance (FIG. 3A).

Next, a semiconductor active layer 23 is placed in the semiconductor substrate 1 on the main surface 2.
Each part is formed to have a uniform thickness by implanting impurity ions from the side (FIG. 3B).

Next, a source electrode 6 is placed on the peripheral portion 24 of the semiconductor active layer 23.
and a drain electrode 7 are formed in ohmic contact with the peripheral part 24 by a method known per se, and a source electrode 16 is formed on the peripheral part 25 of the semiconductor active layer 23.
At the same time as forming the source electrode 6 and drain electrode 7, the drain electrode 17 is similarly formed so as to be in ohmic contact with the peripheral portion 25 (FIG. 3C).

Next, molybdenum,
A gate electrode 5 made of a material containing silicon and nitrogen is formed so as to form a Schottky junction 4 with the abdomen 24 (FIG. 3D). A gate electrode made of such a material can be easily formed by placing the substrate 1 in an atmosphere for vapor deposition of molybdenum and silicon in which nitrogen gas is flowing.

Next, molybdenum,
A gate electrode 15 made of a material containing silicon and nitrogen but having a composition ratio different from that of the gate electrode 5 is formed so as to form a Schottky junction 24 with the abdomen 24 (FIG. 3E). A gate electrode made of such a material can be formed by placing the substrate 1 in the same atmosphere as when forming the gate electrode 5, but in this case, the Schottky barrier to the flow rate ratio (%) of nitrogen gas is Since the relationship shown in FIG. 4 exists, the flow rate ratio of nitrogen gas may be reduced when forming the gate electrode 5, or the concentration of the substrate 1 may be reduced to reduce the activity of nitrogen against molybdenum and silicon. The concentration is lower than that when forming the electrode 5.

In the manner described above, the semiconductor device according to the first invention of the present application shown in FIG. 2 is manufactured.

The above is the actual process of manufacturing a semiconductor device according to the second invention of the present application. According to such a manufacturing method, it is possible to easily produce a target semiconductor device with a simple process. can.

In addition, in the above description, only one embodiment has been shown for each of the semiconductor devices and manufacturing methods thereof according to the first and second inventions of the present application, and for example, the gate electrode 5 may be made of molybdenum or silicon and nitrogen. Various modifications and changes may be made without departing from the spirit of the invention, such as making the gate electrode 5 made of molybdenum or silicon.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a conventional semiconductor device. FIG. 2 is a linear sectional view showing an embodiment of a semiconductor device according to the first invention of the present application. 3A to 3F are line sectional views showing sequential steps showing an embodiment of a method for manufacturing a semiconductor device according to the second invention of the present application, which manufactures the semiconductor device according to the first invention of the present application shown in FIG. It is. FIG. 4 shows the flow rate ratio of nitrogen gas (
%) and the height of the Schottky barrier. 1... Semiconductor substrate 2... Principal surface ET of semiconductor substrate...
・Enhancement type Schott 1-K junction type field effect l
- Transistor 3... Semiconductor active layer 4 of Schottky junction field effect transistor E... Schottky junction 5 of Schottky junction field effect transistor ET... . . . Gate electrode 6 of Schottky junction field effect transistor ET . . . Source electrode 7 of Schottky junction field effect transistor ET . . . Schottky junction field effect transistor Drain electrode 9 of ET...Depletion layer DT in Schottky junction field effect transistor ET...Depletion type Schottky junction field effect transistor 13...Schottky junction type Semiconductor active layer 14 of field effect transistor DT... Schottky junction 15 of Schottky junction field effect transistor DT... Gate electrode of Schottky junction field effect transistor DT 16... Source electrode 17 of Schottky junction field effect transistor DT... Drain electrode 18 of Schottky junction field effect transistor...@pole 19... In Schottky junction field effect transistor DT Depletion layer number one! ! r Dan Engineering■ Figure 2 2 Mountain Figure 3 Figure 3 @ 4 pieces - Unification, + tzu) Procedural amendment 1984.2 p. Day 2, Title of invention Semiconductor device and method for manufacturing the same 3 , Relationship to the case of the person making the amendment Patent applicant address 1-1-6 Uchisaiwai-cho, Chiyoda-ku, Tokyo Name Name
(422) Nippon Telegraph and Telephone Public Corporation Representative Tsune Shinfuji 4, Agent address 5-7 Kojimachi, Chiyoda-ku, Tokyo 102
Hidekazu Kioicho TBR No. 820 No. 5, Date of amendment order Voluntary amendment 6, Number of inventions increased by amendment None Description (corrected full text) 1. Title of invention Semiconductor device and manufacturing method thereof 2. Scope of claim 1. On substrate a first semiconductor active layer formed in the first semiconductor active layer;
a first gate electrode attached to form a first Schottky junction on the semiconductor active layer, and a position sandwiching the first gate electrode on the first semiconductor active layer;
an enhancement-type first electrode having a first source electrode and a first drain electrode each ohmically attached;
a Schottky junction field effect 1~ transistor, a second semiconductor active layer formed on a substrate, and a second semiconductor active layer formed on the second semiconductor active layer to form a second Schottky junction. A depletion type semiconductor device comprising a gate electrode, and a second source electrode and a second drain electrode ohmically attached to the second semiconductor active layer at positions sandwiching the second gate electrode, respectively. 2, the first and second semiconductor active layers are first and second reservoirs of the semiconductor active layer common to them, and the first gate electrode is the first and second semiconductor active layers; The second gate electrode is formed of a first material forming a first Schottky barrier by the first Schottky junction between the first reservoir as a semiconductor active layer, and the second gate electrode formed of a second material that forms a second Schottky barrier lower than the first Schottky barrier due to the second Schottky junction between the second reservoir serving as the semiconductor active layer of the semiconductor active layer; A semiconductor device characterized in that the second material of the second gate electrode contains the same elements as the first material of the first gate electrode but has a different composition ratio. 2. In the semiconductor device according to claim 1, the first gate N[! The first material of the second gate electrode includes molybdenum and silicon, and the second material of the second gate electrode includes molybdenum.
A semiconductor device comprising silicon and nitrogen and having a composition ratio different from that of the first material. 3. Forming a semiconductor active layer on the substrate to have a uniform thickness in each part; and forming a first gate electrode made of a first material on a first circumference of the semiconductor active layer. forming a first Schottky junction forming a first Schottky barrier between the first gate electrode and the second reservoir, and after or before forming the first gate electrode,
A second material containing the same elements as the first material but having a different composition ratio is formed on the second peripheral portion of the semiconductor active layer.
a second gate electrode made of a material such that a second Schottky junction forming a second Schottky barrier lower than the first Schottky barrier is formed between the second gate electrode and the second reservoir; After or before forming either or both of the first and second gate electrodes, sandwiching the first gate electrode on a first peripheral portion of the semiconductor active layer. a first source electrode and a first drain electrode are formed in an ohmic connection with the first reservoir, and a first source electrode and a first drain electrode are formed on the second circumferential portion of the semiconductor active layer. forming a second source electrode and a second drain electrode at positions sandwiching the second goo electrodes so as to be ohmically connected to the second reservoir; Characteristic semiconductor device manufacturing method. 4. In the method for manufacturing a semiconductor device according to claim 3, the first gate electrode is formed using a deposition method using a first raw material serving as the first material, and the second The gate electrode is formed using a deposition method using a second raw material containing the same elements as the first raw material serving as the second material but having a different composition ratio. A method for manufacturing semiconductor devices. 5. The method for manufacturing a semiconductor device according to claim 4, wherein the first and second raw materials contain molybdenum, silicon, and nitrogen. 6. The method for manufacturing a semiconductor device according to claim 3, wherein the first gate electrode is made of a first material that is the first material, with the semiconductor active layer being the first material. The second gate electrode is formed using a deposition method using raw materials, and the semiconductor active layer is formed using a deposition method using a raw material.
The above-mentioned second material is made of a second material different from the material of
A method for manufacturing a semiconductor device, characterized in that the semiconductor device is formed by a deposition method using a second raw material containing the same element as the first raw material. 7. The method for manufacturing a semiconductor device according to claim 6, wherein the first and second raw materials contain molybdenum, silicon, and nitrogen. 3. Detailed Description of the Invention Field of the Invention The present invention relates to a semiconductor device having an enhancement type Schottky junction field effect transistor and a depletion type Schottky junction field effect transistor, and a method for manufacturing the same. Background of the Invention As a semiconductor device having an enhancement type Schottky junction field effect transistor and a depletion type Schottky junction field effect transistor,
A device having the configuration described below with reference to FIG. 1 has been proposed. That is, using a semi-insulating or P-type or N-type semiconductor substrate 1 made of G'aAS, for example, an enhancement type Schottky junction field effect transistor ET and a depletion type Schottky junction field effect transistor DT are formed. is configured. In the Schottky junction field effect transistor ET, impurity ions that give P type or N type when the semiconductor substrate 1 has semi-insulating properties, and In the case of N type, the semiconductor active layer 3 is formed by implanting impurity ions that give a conductivity type opposite to that of the semiconductor substrate. Furthermore, the Schottky junction field effect transistor ET is
A gate electrode 5 is attached to form a Schottky junction 4 on the semiconductor active layer 3, and a source electrode 6 and a drain electrode are ohmically attached to the semiconductor active layer 3 at positions sandwiching the gate electrode 5, respectively. 7. On the other hand, the Schottky junction field effect transistor DT has a semiconductor active layer 13 formed in the semiconductor substrate 1 from the main surface 2 side in the same manner as the semiconductor active layer 3 . In this case, the semiconductor active layer 13 has the same thickness as the semiconductor active layer 3 but has a higher carrier concentration than the semiconductor active layer 3, or as shown in the figure, the semiconductor active layer 13 has the same thickness as the semiconductor active layer 3 but has a higher carrier concentration than the semiconductor active layer 3. Although having the same carrier concentration, the semiconductor active layer 3
It has a thicker thickness than the . Further, the semiconductor active layers 3 and 13 are connected to each other. Further, the Schottky junction field effect transistor DT includes a gate electrode 15 (=I) on the semiconductor active layer 13 to form a Schottky junction 14 and a gate electrode 15 on the semiconductor active layer 13. At the positions shown in FIG. Furthermore, the source electrode 16 and the drain electrode 7 of the above-described junction field effect transistor ET are common to the source electrodes 16 and 7 extending across the connection position of the semiconductor active layers 3 and 13. The semiconductor active layers 13 and 3 side of the electrode 18 are described above.The above describes the conventionally proposed semiconductor device having an enhancement type Schottky junction field effect transistor and a depletion type Schottky junction field effect transistor. According to this configuration, in the enhancement type Schottky junction field effect transistor ET, the semiconductor active layer is removed from the Schottky junction 4 in a state where no control voltage is applied between the gate electrode 5 and the source electrode 6. As shown in the figure, a depletion layer 9 is formed extending toward the semiconductor substrate 1. Therefore, in this state, the source electrode 6 Even if a required power source is connected between the source electrode 6 and the drain electrode 7, a current cannot flow through the semiconductor active layer 3 to the outside through the source electrode 6 and the drain electrode 7. However, from this state, the gate If a control voltage is applied between the electrode 5 and the source electrode 6 with the required polarity, the depletion layer 9 that has spread in the semiconductor active layer 3 until it reaches the semiconductor substrate 1 will change to the value of the control voltage. Therefore, if a required power source is connected between the source electrode 6 and the drain electrode 7 at this time, the inside of the semiconductor active layer 3 is moved back toward the Schottky junction 4 side. A current flows to the outside through 7, with a value corresponding to the fiI1m voltage.Furthermore, in the depletion type Schottky junction field effect transistor D, there is a state in which no control voltage is applied between the gate electrode 15 and the source electrode 16. However, even when a control voltage with the required polarity is applied between the gate electrodes 15 and 16, a depletion layer 19 is formed extending from the Schottky junction 14 toward the semiconductor active layer 13. As shown in the figure, the semiconductor substrate 1
This has not been achieved. For this reason, the source electrode 16
If a required power source is connected between the source electrode 16 and the train electrode 17, a current can be obtained that flows inside the semiconductor active layer 13 through the source electrode 16 and the drain electrode 17 to the outside. Therefore, according to the conventional semiconductor device shown in FIG. 1, the gate electrode 1 of the Schottky junction field effect transistor DT is
5 is connected to the source electrode 16 of the Schottky junction field effect transistor DT, and a necessary power supply is connected between the source electrode 16 of the Schottky junction field effect transistor ET and the drain electrode 17 of the Schottky junction field effect transistor DT. If a control voltage is applied between the gate electrode 5 and the source electrode 6 of the Schottky junction field effect transistor ET, the drain electrode 7 of the Schottky junction field effect transistor ET and the Schottky junction field effect transistor ET are Source electrode 1 of field effect transistor DT
6 and the source electrode 6 of the Schottky junction field effect transistor ET, an output voltage corresponding to the control I lightning voltage is obtained. Therefore, it is possible to obtain a function as an inverter using the Schottky junction field effect transistor ET as a drive transistor and the Schottky junction field effect transistor DT as a load. In this way, according to the conventional semiconductor device shown in FIG.
The function as an inverter can be obtained, but for this purpose, the semiconductor substrates 1 have the same thickness but different carrier concentrations, or have the same carrier concentration but mutually different carrier concentrations. Two semiconductor active layers 3 with different thicknesses
and 13 need to be formed. Therefore, it has the disadvantage that many steps are required to manufacture the semiconductor device. According to the disclosure of the present invention, it is an object of the present invention to propose a novel semiconductor device and a method for manufacturing the same that is free from the above-mentioned drawbacks. The semiconductor device according to the first invention of the present application has the following configuration similar to the conventional semiconductor device described above in FIG. That is, a first semiconductor active layer formed on a substrate;
a first gate electrode attached to form a first Schottky junction on the first semiconductor active layer; and a position sandwiching the first gate electrode on the first semiconductor active layer;
an enhancement-type first electrode having a first source electrode and a first drain electrode each ohmically attached;
It has a Schottky junction field effect transistor. Further, a second semiconductor active layer formed on the above-described substrate, a second gate electrode attached to form a second Schottky junction on the second semiconductor active layer, and a second semiconductor active layer formed on the substrate described above; A second depletion type Schottky junction field effect transistor having a second source electrode and a second drain electrode ohmically attached on the semiconductor active layer at positions sandwiching the second gate electrode. have However, the semiconductor device according to the first invention of the present application has the following configuration in the semiconductor device having the above-described configuration. That is, the first and second semiconductor active layers consist of first and second flanks of a semiconductor active layer common to them. Further, the first gate electrode is formed of a first material forming a first Schottky barrier by a first Schottky junction between the first gate electrode and the first abdomen as the first semiconductor active layer,
Meanwhile, the second gate electrode is formed of a second material that forms a second Schottky barrier that is lower than the first Schottky barrier caused by the first Schottky junction. In this case, the second material of the second gate electrode contains the same elements as the first material of the first glue electrode, but has a different composition ratio. The above is the configuration of the semiconductor device according to the first invention of the present application. According to the semiconductor device according to the first invention of the present application having such a configuration, the first semiconductor active layer for an enhancement type Schottky junction field effect transistor and the second semiconductor active layer for a depletion type Schottky junction field effect transistor are provided. Since the semiconductor active layers of the semiconductor active layers are formed by the first and second regions of the semiconductor active layer common to them, the two semiconductor active layers are separately placed on the substrate, as in the conventional semiconductor device described above in FIG. No need to form. Further, according to the semiconductor device according to the first invention of the present application,
The first gate electrode for the enhancement type Schottky junction field effect transistor and the M2 gate electrode for the depletion type Schottky junction field effect transistor contain the same element but have different composition ratios. However, since the first and second gate electrodes contain the same element and have different composition ratios, The second gate electrode can be easily formed. Therefore, the semiconductor device according to the first invention of the present application has the feature that the semiconductor device can be manufactured more easily than the conventional semiconductor device described above in FIG. Further, the method for manufacturing a semiconductor device according to the second invention of the present application is as follows:
A semiconductor device according to the first invention of the present application is manufactured by taking the steps described below. That is, a step is taken in which a semiconductor active layer is formed on a substrate to have a uniform thickness at each portion. Next, a first gate electrode made of a first material is placed on the first circumferential portion of the semiconductor active layer, and a first Schottky barrier is formed between the first gate electrode and the first abdomen. The second body of the semiconductor active layer includes the same element as the first material in the forming step and after or before forming the first gate electrode so as to form a junction. a second gate electrode made of a second material having a different composition ratio;
A forming step is taken to form a second Schottky junction that forms a second Schottky barrier lower than the first Schottky barrier with the abdomen of the second Schottky barrier. Further, after or before forming one or both of the first and second goo 1 to electrodes, J5 is placed on the first body of the semiconductor active layer at a position sandwiching the first gate electrode. ,
forming a first source electrode and a first drain electrode in ohmic contact with the first abdomen;
A second source electrode and a second train electrode are formed on the second peripheral portion of the semiconductor active layer at positions sandwiching the second gate electrode so as to be in ohmic contact with the second abdomen. Take the process of The above is the method for manufacturing a semiconductor device according to the second invention of the present application. According to the method for manufacturing a semiconductor device according to the second invention of the present application, the steps include forming a semiconductor active layer on a substrate, and forming a first goo electrode on the first abdomen of the semiconductor active layer. a step of forming a second gate electrode on a second peripheral portion of the semiconductor active layer; and a step of forming a first source electrode and a first gate electrode on the first and second peripheral portions of the semiconductor active layer, respectively. The step of forming the drain electrode, the second source electrode, and the second train electrode is very simple.The step of forming the first and second gate electrodes is the second gate electrode. This is a slightly different process in that the first gate electrode is formed using a material that contains the same elements as the first gate electrode but has a different composition ratio. It has the characteristics that it can be manufactured easily and with good reproducibility. A Rainbow Embodiment of the Semiconductor Device According to the First Invention of the Present Application First, an embodiment of the semiconductor device according to the first invention of the present application will be described with reference to FIG. In FIG. 2, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed descriptions are omitted. The embodiment of the semiconductor device according to the first invention of the present application shown in FIG. 2 has the same structure as the conventional semiconductor device shown in FIG. 1 except for the following points in the structure described above in FIG. That is, impurity ions are formed in the semiconductor active layers 3 and 13 in the semiconductor substrate 1 from the main surface 2 side, similar to the case where the semiconductor active layers 3 and 13 of the conventional semiconductor device described above in FIG. It consists of reservoirs 24 and 25 of the semiconductor active layer 23 which are common to the semiconductor active layers 3 and 13 and formed by the above. Furthermore, the gate electrode 5 of the enhancement 1-type Schottky junction field effect transistor ET is connected to the semiconductor active layer 3.
The Schottky barrier formed by the Schottky junction 4 is made of a material containing molydodenum, silicon, and nitrogen, and the Schottky barrier formed by the Schottky junction 4 has a height of 0.9 to 1.0 V. It is formed as something that has. Further, the gate electrode 15 of the depletion type Schottky junction field effect transistor ET is connected to the semiconductor active layer 13.
The Schottky junction 14 is made of a material that forms a lower Schottky barrier than the Schottky barrier caused by the Schottky junction 4 described above. In this case, the material of the gate electrode 15 contains molybdenum, silicon, and nitrogen, which are the same elements as the material of the gate electrode 5, or contains only a small amount of nitrogen compared to the case of the gate electrode 5. , has a composition ratio different from that of the material of the gate electrode 5, and is formed so that the Schottky barrier due to the Schottky junction 14 has a height of 0.45 to 0.55V. Furthermore, a source electrode 6 and a drain electrode 7 of an enhancement type Schottky junction field effect transistor ET
However, the reservoir 2 of the semiconductor active layer 23 as the semiconductor active layer 3
4, and the source electrode 16 and drain electrode 17 of the depletion type Schottky junction field effect transistor ET are ohmically attached to the reservoir 25 of the semiconductor active layer 23 as the semiconductor active layer 13. . The above is the configuration of the embodiment of the semiconductor device according to the first invention of the present application. According to this configuration, except for the matters mentioned above, it has the same configuration as the conventional semiconductor device described above in FIG. It can function as an inverter. However, according to the semiconductor device according to the first invention of the present application shown in FIG. 2, the semiconductor active layer 3 of the enhancement type Schottky junction field effect transistor F;
Since the semiconductor active layer 13 of the depletion type Schottky junction field effect transistor DT consists of the reservoirs 24 and 25 of the semiconductor active layer 23 common to these, the semiconductor active layers 3 and 13 can be easily formed. I can do it. Further, the gate electrode 5 of the enhancement type Schottky junction field effect transistor ET and the gate electrode 15 of the depletion type Schottky junction field effect transistor ET each contain the same element, and the composition ratio is Since the gate electrodes 5 and 15 are only different from each other, the gate electrodes 5 and 15 can be easily formed. Therefore, the semiconductor device according to the first aspect of the present invention shown in FIG. 2 has the feature that the semiconductor device can be formed more easily than the case shown in FIG. Next, the embodiment of the method for manufacturing a semiconductor device according to the second invention of the present application is applied to the method of manufacturing a semiconductor device according to the first invention of the present application shown in FIG. Let's talk about the case. In FIGS. 3A to 3D, parts corresponding to those in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. A method for manufacturing a semiconductor device according to the second invention of the present application shown in FIGS. 3 to 3D includes the following sequential steps to manufacture the semiconductor device according to the first invention of the application shown in FIG. That is, the semiconductor substrate 1 is prepared in advance (FIG. 3A). Next, a semiconductor active layer 23 is placed in the semiconductor substrate 1 on the main surface 2.
Each part is formed to have a uniform thickness by implanting impurity ions from the side (FIG. 3B). Next, a source electrode 6 is placed on the peripheral portion 24 of the semiconductor active layer 23.
and a drain electrode 7 are formed in ohmic contact with the reservoir 24 by a method known per se, and a source electrode 16 is formed on the abdomen 25 of the semiconductor active layer 23.
At the same time as the source electrode 6 and drain electrode 7 are formed, the drain electrode 17 is similarly formed so as to be in ohmic contact with the reservoir 25 (FIG. 3C). Next, on the peripheral portion 24 of the semiconductor active layer 23, molybdenum,
A gate electrode 5 made of a material containing silicon and nitrogen is formed so as to form a Schottky junction 4 with the reservoir 24 (FIG. 3D). A gate electrode made of such a material can be easily formed by placing the substrate 1 in an atmosphere for vapor deposition of molybdenum and silicon in which nitrogen gas is flowing. Next, on the abdomen 25 of the semiconductor active layer 23, molybdenum,
A gate electrode 15 made of a material containing silicon and nitrogen but having a composition ratio different from that of the gate electrode 5 is formed so as to form a Schottky junction 24 with the reservoir 24 (FIG. 3E). A gate electrode made of such a material can be formed by placing the substrate 1 in the same atmosphere as that used to form the gate electrode 5, but in this case, the Schottky barrier to the flow rate ratio (%) of nitrogen gas is Since the relationship shown in FIG. 4 is established, the flow rate ratio of nitrogen gas may be reduced when forming the gate electrode 5, or the concentration of the substrate 1 may be reduced in order to weaken the activity of nitrogen toward molybdenum and silicon. The concentration is lower than that when forming the gate electrode 5. In the manner described above, the semiconductor device according to the first invention of the present application shown in FIG. 2 is manufactured. The above is an embodiment of the method for manufacturing a semiconductor device according to the second invention of the present application. According to such a manufacturing method, a target semiconductor device can be easily manufactured through simple steps. In addition, in the above description, only one embodiment has been shown for each of the semiconductor devices and manufacturing methods thereof according to the first and second inventions of the present application, and for example, the gate electrode 5 may be made of molybdenum or silicon and nitrogen. Various modifications and changes may be made without departing from the spirit of the invention, such as making the gate electrode 5 made of molybdenum or silicon. 4. Brief Description of the Drawings FIG. 1 is a cross-sectional view showing a conventional semiconductor device. FIG. 2 is a linear sectional view showing an embodiment of a semiconductor device according to the first invention of the present application. 3A to 3E are line sectional views showing sequential steps showing an embodiment of a method for manufacturing a semiconductor device according to the second invention of the present application, which manufactures the semiconductor device according to the first invention of the present application shown in FIG. It is. FIG. 4 shows the flow rate ratio of nitrogen gas (
%) and the height of the Schottky barrier. 1... Semiconductor substrate 2... Principal surface ET of semiconductor substrate...
- Enhancement type Schottky junction, mold field effect transistor 3... Semiconductor active layer 4 of Schottky junction field effect transistor ET... Schottky junction field effect transistor ET Schottky junction 5... Gate electrode 6 of Schottky junction field effect transistor ET... Source electrode 7 of Schottky junction field effect transistor ET... Drain electrode 9 of Schottky junction field effect transistor ET Depletion layer DT in Schottky junction field effect transistor ET Depletion type Schottky junction field effect transistor 13 ... Semiconductor active layer 14 of Schottky junction field effect transistor DT ... Schottky junction 15 of Schottky junction field effect transistor DT ... Gate of Schottky junction field effect transistor DT Electrode 16... Source electrode 17 of Schottky junction field effect transistor DT... Train electrode 18 of Schottky junction field effect transistor... Electrode 19... Schottky Depletion layer in junction field effect transistor DT Applicant: Nippon Telegraph and Telephone Public Corporation 1X Tsuboto, Masutsuboji, Takou Shugo, '・

Claims (1)

[Claims] 1. A first semiconductor active layer formed on a substrate;
a first gate electrode attached to form a first Schottky junction on the semiconductor active layer, and a position sandwiching the first gate electrode on the first semiconductor active layer;
a first Schottky junction field effect transistor of an enhancement type, each having a first source electrode and a first drain electrode that are ohmic (=I); a second semiconductor active layer formed on a substrate; a second gate electrode attached to form a second Schottky junction on the second semiconductor active layer; and a second gate electrode on the second semiconductor active layer at a position sandwiching the second gate electrode. , a depletion transistor having a second source electrode and a second train electrode which are ohmically attached, respectively, wherein the first and second semiconductor active layers have a common semiconductor active layer. between the first gate electrode and the first abdomen as the first semiconductor active layer, a first Schottky junction formed by the first Schottky junction; The second gate electrode is formed of a first material forming a barrier, and the second gate electrode is connected to the first material by the second Schottky junction between the second abdomen and the second semiconductor active layer. The second gate electrode is formed of a second material forming a second Schottky barrier lower than the Schottky barrier, and the second material of the second gate electrode contains the same element as the first material of the first gate electrode. A semiconductor device characterized in that the first material of the first gate electrode contains molybdenum and has a different composition ratio.
the second material of the second gate electrode comprises molybdenum;
A semiconductor device comprising silicon and nitrogen and having a composition ratio different from that of the first material. 3. Forming a semiconductor active layer on the substrate to have a uniform thickness in each part; and forming a first gate electrode made of a first material on the first step of the semiconductor active layer. forming a first Schottky junction forming a first Schottky barrier between the abdomen of the first gate electrode, and after or before forming the first gate electrode,
A second layer containing the same elements as the first material but having a different composition ratio is formed on the second level of the semiconductor active layer.
forming a second gate electrode made of a material such that a second Schottky junction forming a second Schottky barrier lower than the first Schottky barrier is formed between the second gate electrode and the second abdomen; After or before forming either or both of the first and second gate electrodes, a position sandwiching the first gate electrode on the first partition of the semiconductor active layer. A first source electrode and a first drain electrode are formed to be ohmically connected to the first abdomen, and the second electrode is formed on the second step of the semiconductor active layer. forming a second source electrode and a second drain electrode at positions sandwiching the gate electrode so as to be ohmically connected to the second abdomen. Manufacturing method. 4. In the method for manufacturing a semiconductor device according to claim 3, the first gate electrode is formed using a deposition method using a first raw material serving as the first material, and the second The gate electrode is formed using a deposition method using a second raw material containing the same elements as the first raw material serving as the second material but having a different composition ratio. A method for manufacturing semiconductor devices. 5. The method for manufacturing a semiconductor device according to claim 4, wherein the first and second raw materials contain molybdenum, silicon, and nitrogen. 6. The method for manufacturing a semiconductor device according to claim 3, wherein the first gate electrode is made of a first material, which is the first material, in a state where the semiconductor active layer is at a first temperature. The second gate electrode is formed using a deposition method using raw materials, and the semiconductor active layer is formed using a deposition method using a raw material.
The above-mentioned second temperature is set to a second temperature different from the temperature of
A method for manufacturing a semiconductor device, characterized in that the semiconductor device is formed by a deposition method using a second raw material containing the same element as the first raw material. 7. The method for manufacturing a semiconductor device according to claim 6, wherein the first and second raw materials contain molybdenum, silicon, and nitrogen.