JP2002280574A - Semiconductor device, manufacturing method therefor and millimeter wave band communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device which facilitates an integrating diode having negative resistance and a Schottky diode having a Schottky characteristic on the same substrate, a manufacturing method therefor and a millimeter wave band communication apparatus. SOLUTION: A laminate structure having the Schottky diode characteristic and a laminate structure having a negative resistance diode characteristic are formed by epitaxial growth on a semi-insulative GaAs substrate 101. The device comprises a GUNN diode 11 with an anode Ohmic electrode 111 and a cathode Ohmic electrode 112 formed in a region A, the first Schottky diode 12 with a Schottky electrode 116 formed in a region B and a second Schottky diode 13 with the Schottky electrode 116 formed on a low concentration semiconductor layer 103 at the Schottky electrode and an Ohmic electrode 114 formed on a high concentration semiconductor layer 102 at the Ohmic electrode in a region C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device in which different semiconductor elements are integrated on the same substrate, a method of manufacturing the same, and a millimeter-wave band communication device.

[0002]

2. Description of the Related Art Recently, a millimeter wave band (30 GHz to 90 GHz) has been used.
In such a case, a transistor such as an HBT (heterojunction bipolar transistor) or a HEMT (high electron mobility transistor) is used as an oscillation element or an amplifier, and a Schottky diode is used for a varactor or a mixer. Further, there is a semiconductor device integrated by manufacturing those elements on the same substrate (Japanese Patent Laid-Open No.
64929 and JP-A-63-129656.

However, when an HBT or HEMT is used as an oscillating element in the millimeter wave band, the emitter width must be reduced (1 μm) in order to cope with an increase in the frequency of the transistor.
m or less) or miniaturization of the gate length (0.2 μm or less) requires a reduction in parasitic capacitance and a reduction in parasitic resistance, which requires a complicated process, which causes a reduction in yield. Further, when the emitter width and the gate length are miniaturized, there is a problem that the amount of current becomes small and it becomes difficult to obtain an output power required as an oscillation element.

Therefore, as a semiconductor device which solves these problems, there is a semiconductor device using a diode having a negative resistance as an oscillating element instead of an HBT or a HEMT (Japanese Patent Application Laid-Open No. HEI 1-1990).
-112827). In this semiconductor device, FIG.
As shown in (c), TiW80 is formed on the p ⁺ -GaAs layer 805.
6 / Au 807 electrode, and an n ⁺ -GaAs layer 802
A negative resistance IMPATT (Impact Ionization Avalanche T) having a Ti808 / Au809 electrode provided thereon.
(ransit Time) diode, and a microstrip patch composed of Ti810 / Au811 on a semi-insulating GaAs substrate 801. Furthermore, it can be integrated with other devices on a semi-insulating GaAs substrate 801, n ⁺ -
It is disclosed that other devices can be integrated using the GaAs layer 802.

Hereinafter, the structure and manufacturing method of the semiconductor device will be described with reference to FIG.

As shown in FIG. 18A, first, a semi-insulating G
An n ⁺ -GaAs layer 802 (concentration 1 × 1) is formed on an aAs substrate 801.
0 ¹⁹ cm ⁻³ , thickness 1.5 μm), n-GaAs layer 803 (concentration 2 × 10 ¹⁷ cm ⁻³ , thickness 0.25 μm), p-GaAs layer 80
4 (concentration 2 × 10 ¹⁷ cm ^-3 , thickness 0.25 μm), p ⁺ -Ga
An As layer 805 (concentration: 1 × 10 ¹⁹ cm ⁻³ , thickness: 0.2 μm) is sequentially epitaxially grown. Next, after applying a photoresist, a circle having a diameter of 5 μm is patterned and T
An electrode of iW806 (thickness: 100 nm) / Au807 (400 nm) is formed. Next, by wet etching, TiW
Using the 806 (100 nm thick) / Au 807 (400 nm) electrode as an etching mask, the p ⁺ -GaAs layer 805, p
-GaAs layer 804, n-GaAs layer 803, n ⁺ -GaAs layer 8
02, and the etching is stopped in the n ⁺ -GaAs layer 802.

Next, as shown in FIG. 18B, a photoresist is applied to pattern a square of 75 μm on a side, and Ti808 (100 nm) / Au8 is formed by a lift-off method.
09 (400 mn) electrodes are formed. At this time, the electrode
(808, 809) are self-aligned to the electrodes (806, 807).

Next, as shown in FIG. 18C, n ⁺ -Ga
The As layer 802 and a part (about 100 nm) of the semi-insulating GaAs substrate 801 are subjected to anisotropic plasma etching. As a result, the IMPATT diode is isolated as a mesa on the semi-insulating GaAs substrate 801. Thereafter, Ti810 (100 nm) / Au811 (400 n
m) with a semi-insulating Ga
It is formed on an As substrate 801.

Further, IMPATT having the above-mentioned negative resistance
In a semiconductor device using a diode, other elements can be integrated on the semi-insulating GaAs substrate 801 immediately before forming the microstrip patches (810, 811). In particular, active element regions can be formed by ion implantation into the semi-insulating GaAs substrate 801 away from the IMPATT diode and microstrip patch regions. Instead, the n ⁺ -GaAs layer 802
In the step of etching, use another photolithographic mask to preserve the area of the n ⁺ doped GaAs layer 802 for fabrication of other active devices, separated from the area of the IMPATT diode and microstrip patch. can do. The IMPATT diode manufactured as described above can respond to the millimeter wave band without being miniaturized as compared with the HBT and the HEMT, and thus has advantages such as easy processing and high output power as an oscillation element.

[0010]

In a semiconductor device using an IMPATT diode having a negative resistance, ion implantation is used as a method for manufacturing an active device other than the IMPATT diode on a semi-insulating substrate. Therefore, it is necessary to perform a high-temperature (for example, about 600 ° C.) heat treatment (annealing) after the ion implantation in order to activate the ion-implanted region. Due to this heat treatment, there is a problem that the contact resistance and the epitaxial structure of the previously manufactured IMPATT diode portion are deteriorated (heterojunction deterioration, concentration profile deterioration).

The n ⁺ -GaAs layer 802, which is a contact layer of the IMPATT diode, has electrodes (808, 80).
9) are high n ⁺ doped in order to reduce the contact resistance, when using the n ⁺ -GaAs layer 802 to produce the active elements other than IMPATT diode, for example, ME
The Schottky characteristics required for the gate electrode of the SFET and the Schottky electrode of the Schottky diode are high concentration n ⁺ -
There is a problem that it cannot be obtained with the GaAs layer 802.

As described above, in the above-described semiconductor device, it is difficult to obtain desired characteristics even if a diode having a negative resistance and a Schottky diode are formed on the same substrate, and further, reproducibility cannot be obtained. .

It is an object of the present invention to provide a semiconductor device in which a diode having a negative resistance without deterioration of contact resistance and an epitaxial structure and a Schottky diode having good Schottky characteristics can be easily integrated on the same substrate. An object of the present invention is to provide a device and a method of manufacturing the same, and to provide a low-loss, high-performance millimeter-wave band communication device using the semiconductor device.

[0014]

In order to achieve the above object, a semiconductor device according to a first aspect of the present invention is formed by epitaxial growth on a semi-insulating substrate, and includes at least an ohmic electrode-side high-concentration semiconductor layer and a Schottky electrode-side low-concentration semiconductor layer. A semiconductor device comprising: a stacked structure having a Schottky diode characteristic in which concentration semiconductor layers are sequentially stacked; and a stacked structure having a negative resistance diode characteristic formed by epitaxial growth on the stacked structure having the Schottky diode characteristic. A diode having a negative resistance in which the anode ohmic electrode and the cathode ohmic electrode are formed and a region other than the formation region of the diode having the negative resistance are provided in the laminated structure having the negative resistance diode characteristic. And the active structure of the laminated structure having the above negative resistance diode characteristics. A first Schottky diode in which a Schottky electrode is formed on a layer, and a region other than the formation region of the diode having the negative resistance and the formation region of the first Schottky diode; A second Schottky diode in which a Schottky electrode is formed on the Schottky electrode-side low-concentration semiconductor layer having a stacked structure and a ohmic electrode is formed on the Ohmic electrode-side high-concentration semiconductor layer. And

According to the semiconductor device having the above-described structure, a diode having a negative resistance in which an anode ohmic electrode and a cathode ohmic electrode are formed is provided in a laminated structure having a negative resistance diode formed by the epitaxial growth. A first Schottky diode in which a Schottky electrode is formed on an active layer having a stacked structure having the negative resistance diode characteristics is provided in a region other than a region where a diode having a negative resistance is formed. Further, in a region other than the formation region of the diode having the negative resistance and the formation region of the first Schottky diode, a Schottky electrode having a multilayer structure having Schottky diode characteristics formed by epitaxial growth on the semi-insulating substrate. A second Schottky diode in which a Schottky electrode and an ohmic electrode are formed is provided on the low-concentration semiconductor layer on the side and the high-concentration semiconductor layer on the ohmic electrode side. Therefore, since it is not necessary to perform the ion implantation and the high-temperature heat treatment, the problems such as the deterioration of the epitaxial structure and the contact resistance of the diode having the negative resistance are eliminated. In the first Schottky diode,
Since the Schottky electrode is formed on the active layer having a stacked structure having a negative resistance diode characteristic, a Schottky diode having a large capacitance change suitable for use as a varactor diode or the like can be obtained. Since a Schottky electrode is formed on the low-concentration semiconductor layer on the Schottky electrode side and an ohmic electrode is formed on the high-concentration semiconductor layer on the ohmic electrode side, a shot having a small resistance component and a small capacity suitable for use in a mixer or the like. A key diode is obtained. Such a first Schottky diode having a large capacitance change, a second Schottky diode having a small resistance component and a small capacitance, and a diode having a negative resistance can be integrated on the same substrate to reduce signal loss. The size can be reduced.

Further, a semiconductor device according to a second aspect of the present invention includes a laminated structure having a negative resistance diode characteristic formed on a semi-insulating substrate by epitaxial growth, and a laminated structure having the negative resistance diode characteristic formed on the semi-insulating substrate by epitaxial growth. And a stacked structure having a Schottky diode characteristic in which at least an ohmic electrode-side high-concentration semiconductor layer and a Schottky electrode-side low-concentration semiconductor layer are sequentially stacked. A diode having a negative resistance in which an anode ohmic electrode and a cathode ohmic electrode are formed, and provided in a region other than the formation region of the diode having the negative resistance, and having the negative resistance diode characteristic. Having a Schottky electrode formed on an active layer having a laminated structure having A Schottky diode, a low-concentration semiconductor on the Schottky electrode side having a stacked structure having the Schottky diode characteristics, provided in a region other than the formation region of the diode having the negative resistance and the formation region of the first Schottky diode; A second Schottky diode in which a Schottky electrode is formed on the layer and an ohmic electrode is formed on the ohmic electrode-side high-concentration semiconductor layer.

According to the semiconductor device of the above embodiment, the negative resistance in which the anode ohmic electrode and the cathode ohmic electrode are formed is formed in a laminated structure having a negative resistance diode characteristic formed by epitaxial growth on the semi-insulating substrate. A diode having a negative resistance is provided in a region other than the region where the diode having the negative resistance is formed.
A first Schottky diode having a Schottky electrode formed on an active layer having a stacked structure having the negative resistance diode characteristics is provided. Further, in a region other than the formation region of the diode having the negative resistance and the formation region of the first Schottky diode, a Schottky electrode-side low-concentration semiconductor layer having a stacked structure having Schottky diode characteristics formed by the epitaxial growth, A Schottky electrode and a second Schottky diode having the ohmic electrode formed thereon are provided on the high-concentration semiconductor layer on the ohmic electrode side. Therefore, since it is not necessary to perform the ion implantation and the high-temperature heat treatment, the problems such as the deterioration of the epitaxial structure and the contact resistance of the diode having the negative resistance are eliminated. In the first Schottky diode, a Schottky electrode having a large capacitance change suitable for use as a varactor diode or the like is obtained because the Schottky electrode is formed on the active layer having a stacked structure having a negative resistance diode characteristic. In addition, in the second Schottky diode, the Schottky electrode is formed on the low-concentration semiconductor layer on the Schottky electrode side, and the ohmic electrode is formed on the high-concentration semiconductor layer on the ohmic electrode side. A suitable Schottky diode having a small resistance component and a small capacitance is obtained. Such a first Schottky diode having a large capacitance change, a second Schottky diode having a small resistance component and a small capacitance, and a diode having a negative resistance can be integrated on the same substrate to reduce signal loss. The size can be reduced.

In one embodiment of the present invention, in the semiconductor device according to the first aspect, an etching stop layer is laminated on the low-concentration semiconductor layer on the Schottky electrode side.

According to the semiconductor device of the above embodiment, by stacking the etching stop layer on the low concentration semiconductor layer on the Schottky electrode side, the stacked structure having the diode characteristic having the negative resistance is selectively etched. And eliminates over-etching of the low-concentration semiconductor layer on the Schottky electrode side of the second Schottky diode, and reduces the thickness of the low-concentration semiconductor layer on the Schottky electrode side to the thickness at the time of epitaxial growth within the wafer plane. , And variations between wafers can be reduced. Thereby, reproducibility of the characteristics of the second Schottky diode can be obtained.

In one embodiment of the present invention, in the semiconductor device according to the second aspect of the present invention, an etching stop layer is laminated below the low-concentration semiconductor layer on the Schottky electrode side.

According to the semiconductor device of the above embodiment, the etching stop layer is stacked under the Schottky electrode-side low-concentration semiconductor layer of the stacked structure having the Schottky diode characteristic, thereby providing the Schottky electrode-side low-concentration semiconductor. The layer can be selectively etched and removed, so that the stacked structure having a negative resistance diode characteristic is not over-etched, and the active layer of the stacked structure having the negative resistance diode characteristic is formed with a thickness at the time of epitaxial growth. Control can be performed within the wafer plane, and variations between wafers can be reduced. Thereby, reproducibility of the characteristics of the diode having the negative resistance can be obtained.

In one embodiment of the present invention, the diode having a negative resistance is a Gunn diode.

According to the semiconductor device of the above embodiment, since the diode having the negative resistance is a Gunn diode, the oscillation element having a small phase noise and the Schottky diode can be integrated on the same substrate.

In one embodiment, at least two of the diode having the negative resistance, the first Schottky diode, and the second Schottky diode are connected by a transmission line. And

According to the semiconductor device of the above embodiment, the transmission line connecting the devices is shortened by fabricating the diode having the negative resistance and the first and second Schottky diodes on the same substrate. This is very effective in reducing signal loss.

The method of manufacturing a semiconductor device of the present invention is the method of manufacturing a semiconductor device of the first invention,
Forming, by epitaxial growth, a laminated structure having a Schottky diode characteristic in which at least an ohmic electrode side high concentration semiconductor layer and a Schottky electrode side low concentration semiconductor layer are sequentially laminated on a semi-insulating substrate; On the laminated structure having, at least the anode ohmic electrode side high concentration semiconductor layer, the active layer and the cathode ohmic electrode side high concentration semiconductor layer, a step of forming a layered structure having a negative resistance diode characteristic sequentially laminated by epitaxial growth, Forming a diode region having a negative resistance and a first Schottky diode region by selectively etching the stacked structure having the negative resistance diode characteristics;
Forming a second Schottky diode region by selectively etching a stacked structure having the Schottky diode characteristics in a region other than the diode region having the negative resistance and the first Schottky diode region; Forming an isolation region separating the diode region having the negative resistance, the first Schottky diode region, and the second Schottky diode region; and an anode ohmic electrode and a cathode ohmic in the diode region having the negative resistance. Forming an electrode, and forming an ohmic electrode in the first and second Schottky diode regions;
Forming a Schottky electrode in the first and second Schottky diode regions; and forming an anode ohmic electrode, a cathode ohmic electrode in the diode region having the negative resistance, and an ohmic electrode in the first Schottky diode region. Forming a transmission line connecting the electrode and at least two of the ohmic electrode and the Schottky electrode in the second Schottky diode region.

According to the method of manufacturing a semiconductor device described above, since there is no need to perform ion implantation and high-temperature heat treatment, problems such as deterioration of the epitaxial structure and contact resistance of a diode having negative resistance are eliminated. In the first Schottky diode, a Schottky electrode having a large capacitance change suitable for use as a varactor diode or the like is obtained because the Schottky electrode is formed on the active layer having a stacked structure having a negative resistance diode characteristic. In addition, in the second Schottky diode, the Schottky electrode is formed on the low-concentration semiconductor layer on the Schottky electrode side, and the ohmic electrode is formed on the high-concentration semiconductor layer on the ohmic electrode side. A suitable Schottky diode having a small resistance component and a small capacitance is obtained. Such a first Schottky diode having a large capacitance change, a second Schottky diode having a small resistance component and a small capacitance, and a diode having a negative resistance can be integrated on the same substrate to reduce signal loss. The size can be reduced. Further, a semiconductor device having a small in-plane variation in characteristics of the diode having the negative resistance and the first and second Schottky diodes can be easily manufactured on the same substrate.

The method for manufacturing a semiconductor device according to the present invention is the method for manufacturing a semiconductor device according to the second invention, wherein
On a semi-insulating substrate, at least an anode ohmic electrode-side high-concentration semiconductor layer, an active layer and a cathode ohmic electrode-side high-concentration semiconductor layer are sequentially stacked to form a stacked structure having a negative resistance diode characteristic by epitaxial growth, A step of forming a stacked structure having a Schottky diode characteristic in which at least an ohmic electrode-side high-concentration semiconductor layer and a Schottky electrode-side low-concentration semiconductor layer are sequentially stacked on the stacked structure having the negative resistance diode characteristic by epitaxial growth; Forming a second Schottky diode region by selectively etching the laminated structure having the Schottky diode characteristic; and selectively etching the negative structure by selectively etching the laminated structure having the negative resistance diode characteristic. With resistance Forming a diode region and a first Schottky diode region; and forming an isolation region for separating the diode region having the negative resistance, the first Schottky diode region, and the second Schottky diode region; Forming an anode ohmic electrode and a cathode ohmic electrode in the diode region having a negative resistance, and forming ohmic electrodes in the first and second Schottky diode regions; and forming the first and second Schottky diode regions. Forming an anode ohmic electrode, a cathode ohmic electrode of the diode region having the negative resistance and the ohmic electrode of the first Schottky diode region, the Schottky electrode, and the second Schottky diode region. Ohmic electrode Forming a transmission line connecting at least two of the Schottky electrodes.

According to the method of manufacturing a semiconductor device, since there is no need to perform ion implantation and high-temperature heat treatment, problems such as deterioration of the epitaxial structure of a diode having negative resistance and contact resistance are eliminated. In the first Schottky diode, a Schottky electrode having a large capacitance change suitable for use as a varactor diode or the like is obtained because the Schottky electrode is formed on the active layer having a stacked structure having a negative resistance diode characteristic. In addition, in the second Schottky diode, the Schottky electrode is formed on the low-concentration semiconductor layer on the Schottky electrode side, and the ohmic electrode is formed on the high-concentration semiconductor layer on the ohmic electrode side. A suitable Schottky diode having a small resistance component and a small capacitance can be obtained. Such a first Schottky diode having a large capacitance change, a second Schottky diode having a small resistance component and a small capacitance, and a diode having a negative resistance can be integrated on the same substrate to reduce signal loss. The size can be reduced. Further, a semiconductor device having a small in-plane variation in characteristics of the diode having the negative resistance and the first and second Schottky diodes can be easily manufactured on the same substrate.

A millimeter wave band communication device according to the present invention is a millimeter wave band communication device using the semiconductor device, wherein the diode having the negative resistance is used as an oscillation element, and the transmission line is an open stub or It is characterized in that it is used as a short stub, the first Schottky diode is used as a varactor diode, and the second Schottky diode is used as a mixer.

According to the millimeter-wave band communication device having the above configuration, a diode having a negative resistance used as the oscillator;
Since a transmission line used as an open stub or a short stub, a first Schottky diode used as a varactor diode, and a second Schottky diode used as a mixer can be integrated on the same substrate, a negative oscillation element Compared to a circuit in which a diode with resistance and a Schottky diode are fabricated on different wafers and mounted, the loss in the transmission line and the loss in mounting
(Loss of wire bond, etc.) can be reduced, and performance degradation such as deterioration of phase noise can be prevented.

Further, the millimeter-wave band communication device according to one embodiment includes:
The diode having the negative resistance is a Gunn diode.

According to the millimeter-wave band communication device of the above embodiment, an oscillation element having a small phase noise can be obtained by using a diode having a negative resistance as a Gunn diode. The performance of the oscillator is improved.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a semiconductor device, a method of manufacturing the same, and a millimeter-wave band communication device according to the present invention will be described in detail with reference to the illustrated embodiments.

(First Embodiment) FIG. 1 is a sectional view of a Gunn diode / Schottky diode integrated circuit of a semiconductor device according to a first embodiment of the present invention.

In FIG. 1, a Gunn diode 11 as a diode having a negative resistance in a region A, a first Schottky diode 12 having a large capacitance change in a region B, and a second Schottky diode having a small resistance component and a small capacitance in a region C. 13, a transmission line 14 is provided in the region D, respectively.

In the region A, a cathode ohmic electrode 112 of AuGe / Ni / Au and an anode ohmic electrode 111 are provided, and a Gunn diode 11 having an n-GaAs layer 107 serving as an active layer is formed.
On the other hand, in the region B, an ohmic electrode 113 made of AuGe / Ni / Au and an n-GaAs layer 107 serving as an active layer are formed.
And Ti / Au on the n-GaAs layer 107 serving as the active layer.
The first Schottky diode 12 having the Schottky characteristic formed by the conductive film 116 made of is formed. Further, in the region C, the second having the Schottky characteristic formed by the conductive film 116 made of Ti / Au on the ohmic electrode 114 made of AuGe / Ni / Au and the low concentration semiconductor layer 103 on the Schottky electrode side.
A Schottky diode 13 is configured. The periphery of the Gunn diode 11 and the first and second Schottky diodes 12 and 13 are etched to form an isolation region 130 for isolating elements. In the region D, the transmission line 14 including the conductive film 116 and Au 117 is formed.

Next, FIG. 2 to FIG.
FIG. 9 is a cross-sectional view illustrating a step of explaining the method for manufacturing the Schottky diode integrated circuit.

As shown in FIG. 2, MBE (Molecular Beam Epitaxy) or MOCVD (Metal Organic Chemical Vapor Deposition)
An n ⁺ -GaAs layer 102 (Si doping concentration 5 × 10 ^{18) serving as} an ohmic electrode-side high-concentration semiconductor layer for a Schottky diode is formed on a semi-insulating GaAs substrate 101 by a method or the like.
cm ⁻³ , thickness 500 nm), and an n-GaAs layer 103 (Si doping concentration 3
× 10 ¹⁶ cm ⁻³ , thickness 300 nm), and an n-InGaP layer 104 serving as an etching stopper layer (Si doping concentration 5 ×
10 ¹⁸ cm ^-3 , thickness 20 nm), n ⁺ -GaAs to be a high-concentration semiconductor layer on the anode ohmic electrode side for a gun diode
Layer 105 (Si doping concentration 5 × 10 ¹⁸ cm ⁻³ , thickness 5)
00 nm), an n-InGaP layer 106 serving as an etching stopper layer (Si doping concentration 3 × 10 ¹⁸ cm ⁻³ , thickness 20)
n), an n-GaAs layer 107 (Si doping concentration: 2 × 10 ¹⁶ cm ⁻³ , thickness: 2000 nm) as an active layer, and n-Al _x Ga _{1-x as a} cathode layer comprising a wide band gap layer
As layer 108 (X = 0.35, Si doping concentration 5 × 10
¹⁷ cm ⁻³ , thickness 50 nm), n-Al _x Ga _1-x As layer 109
(X = 0.35 → 0Si doping concentration 5 × 10 ¹⁷ cm ^-3 ,
N ⁺ -GaAs layer 110 (Si doping concentration 5 ×) to be a high concentration semiconductor layer on the cathode ohmic electrode side.
10 ¹⁸ cm ^-3 and a thickness of 500 nm) are sequentially epitaxially grown.

The above n ⁺ -GaAs layer 102 and n-GaAs
The layer 103 constitutes a laminated structure having Schottky diode characteristics. Further, the n ⁺ -GaAs layer 105, n-
InGaP layer 106, n-GaAs layer 107, n-Al _x Ga _1-x A
s layer 108, n-Al _x Ga _1-x As layer 109 and n ⁺ -GaAs
The layer 110 constitutes a laminated structure having a negative resistance diode characteristic.

Thereafter, as shown in FIG. 3, the region serving as the cathode of the gun diode is masked with a SiN film 119,
Using an etching solution containing sulfuric acid and hydrogen peroxide or an etching solution containing phosphoric acid and hydrogen peroxide, etc., the n-GaAs layer 1 is used.
Until the 07 is exposed, the n ⁺ -GaAs layer 110, n-Al _x Ga
Predetermined regions of the _1-x As layer 109 and the n-Al _x Ga _1-x As layer 108 are removed by etching. Next, while the SiN film mask 119 is left, the Schottky electrode region for the Schottky diode in the region B is masked with a resist mask 120, and an etching solution containing sulfuric acid and hydrogen peroxide, and phosphoric acid and hydrogen peroxide are used. Using an etching solution containing water, n-
The GaAs layer 107 is removed by etching. The above etching solution hardly etches the n-InGaP layer 106. Next, the n-InGaP layer 106 is removed by etching using hydrochloric acid, thereby exposing the n ⁺ -GaAs layer 105 serving as the anode ohmic electrode side high concentration semiconductor layer. At this time, the hydrochloric acid selectively removes only the n-InGaP layer 106 by etching.

In this manner, etching with a total film thickness of 2000 nm or more can be uniformly and accurately performed within the wafer surface. Further, the mask of the cathode region of the gun diode 11 is not newly formed at the time of forming the mask for forming the Schottky electrode region, but the SiN film mask 119 is reused, so that the n- of the gun diode 11 (shown in FIG. 1) is reduced. GaA
The side wall of the s layer 107 can be etched smoothly without any irregular steps. If there is an irregular step on the side wall of the n-GaAs layer 107, unnecessary frequency components are generated for the oscillation of the Gunn diode 11, and the oscillation power and oscillation efficiency are reduced.

Next, as shown in FIG. 4, a portion of the region A to be the gun diode 11 (shown in FIG. 1) and a first portion of the region B
After masking the portion to be the Schottky diode 12 (shown in FIG. 1) with a photoresist pattern or the like, the n ⁺ -GaAs layer 105 is selectively etched until the n-InGaP layer 104 is exposed in the same manner as the selective etching described above. And remove. Subsequently, the n-InGaP layer 104 is replaced with the n-GaAs layer 1.
03 is selectively etched and removed until 03 is exposed.
At this time, by performing selective etching using the n-InGaP layer 104, the thickness of the n-GaAs layer 103 is accurately controlled. The variation in the film thickness of the n-GaAs layer 103 is caused by the second Schottky diode 13 in the region C.
(Shown in FIG. 1).

Next, the Gunn diode 11 in the area A (FIG. 1)
), A portion serving as the first Schottky diode 12 (shown in FIG. 1) in the region B, and a Schottky electrode region for the second Schottky diode 13 (shown in FIG. 1) in the region C. Mask with a photoresist pattern etc.
The -GaAs layer 103 is removed by etching, n ⁺ -GaAs
The layer 102 is exposed. In the first embodiment, n-Ga
An n-InGaP layer serving as an etching stopper layer is not provided between the As layer 103 and the n ⁺ -GaAs layer 102. This is because the thickness of the n-GaAs layer 103 is not large, and n ⁺ -GaAs
This is because even if the layer 102 is slightly over-etched, an ohmic electrode having no problem for the second Schottky diode 13 can be formed. When the thickness of the n-GaAs layer 103 is increased in order to obtain desired Schottky diode characteristics, the n-GaAs layer 103 has a thickness of n which serves as an etching stopper layer.
It is desirable to provide an -InGaP layer.

Next, as shown in FIG. 5, a portion of the region A to be the gun diode 11 (shown in FIG. 1) and a first portion of the region B
After forming a resist mask by performing resist patterning so as to separate the part to be the Schottky diode 12 (shown in FIG. 1) and the part to be the second Schottky diode 13 (shown in FIG. 1) in the region C, , N ⁺ -Ga
The As layer 102 is etched to separate mesas. At this time, if the separation by ion implantation is performed instead of the mesa separation, the level difference becomes lower than that in the mesa separation, and the subsequent resist coating and patterning becomes easy.

Next, as shown in FIG. 6, the anode ohmic electrode forming region, the cathode ohmic electrode forming region of the gun diode 11 (shown in FIG.
AuGe (100 nm) / Ni (100 nm) / Ni () is deposited on the ohmic electrode forming region of the Schottky diode 12 (shown in FIG. 1) and the ohmic electrode forming region of the second Schottky diode 13 (shown in FIG. 15nm) / Au (1
00 nm), and the ohmic electrode is alloyed by heat treatment at 390 ° C. By doing so, the anode ohmic electrode 111, the cathode ohmic electrode 112, the ohmic electrode 113 and the ohmic electrode 1
14 is formed. Then, a silicon nitride film to be a protective film
(Not shown) is deposited to a thickness of 200 nm to improve reliability. Preferably, the refractive index of the silicon nitride film is 1.9 or more.

Next, as shown in FIG. 7, the resist is left by a resist patterning at a place where a transmission line (wiring) of a step portion of each device (11, 12, 13 shown in FIG. 1) passes, and then the resist is softened. A heat treatment is performed at a desired temperature and reflow is performed to form a resist 115 covering the step. The resist 115 prevents the transmission line from breaking at the step.

Next, as shown in FIG. 1, on the anode ohmic electrode 111 and the cathode ohmic electrode 112 of the Gunn diode 11, the Schottky electrode forming region of the active layer nGaAs 107 of the first Schottky diode 12 in the region B and the ohmic electrode A contact hole (not shown) is formed on the Schottky electrode forming region of the low concentration semiconductor layer 103 on the Schottky electrode side in the region 113 and the ohmic electrode 114. Thereafter, a conductive film 116 of Ti (100 nm) / Au (100 nm) is deposited on the entire surface by an evaporation method or the like. The conductive film 116 is used not only as a power supply metal for forming a transmission line (wiring) thereafter by plating, but also as a Schottky electrode. Although the power supply metal for forming the Schottky electrode and the transmission line 14 by plating is formed at the same time, the Schottky electrode may be formed after the formation of the ohmic electrode of the Schottky diode. In this case, a high melting point metal such as Ti, W or Mo, a high melting point nitride, a high melting point silicide or Al can be used as a Schottky electrode material, but a material which can form a stable Schottky barrier can be used. Is desirable.

Next, a resist having a thickness of 15 μm is applied, and after patterning a region to be the transmission line 14 (116, 117), Au plating of 9 μm thickness is performed.
Thereafter, the resist is removed, and the unnecessary conductive film 11 is removed.
6 is removed by etching and the reflowed resist 115 is further removed, whereby the transmission line 14 (FIG. 1) is removed.
Is formed. In the first embodiment, a coplanar line is used as the transmission line 14, but the semi-insulating G
A microstrip line in which a metal film is formed on the entire back surface of the aAs substrate 101 and the metal film is used as a ground conductor may be used. Also, an NRD (non-radiative dielectric) guide may be used as the transmission line,
In particular, by using the NRD guide in the millimeter wave band, the transmission line becomes a lower loss transmission line as compared with the coplanar line or the microstrip line, and the performance degradation can be prevented.

Although Au plating is used for forming the transmission line 14, Cu plating may be used for cost reduction.

In the first embodiment, wet etching is performed, but dry etching using a chlorine-based gas may be used instead. For dry etching,
Since it is difficult to etch a layer containing In, n-I
The etching of the nGaP layer stops as in the wet etching. In this embodiment, an n-type semiconductor is used for the low-concentration semiconductor layer on the Schottky electrode side of the second Schottky diode 13 in the region C, but a p-type semiconductor may be used. Since a different Schottky electrode material can be used, a wider range of choices can be made when constructing the process. The doping concentration of the low-concentration semiconductor layer on the Schottky electrode side of the second Schottky diode 13 in the region C is, for example, when the mixer is used in a 60 GHz band, the internal resistance is lower than the impedance of the Schottky diode. And specifically, a doping concentration of 2 × 10 ¹⁷ cm ^−3.
It is preferable that the film thickness is not more than 100 nm.
nm.

In the first embodiment, each device (11,
The resist 115 reflowed so as not to break the transmission line 14 at the step of (12, 13) is used. Instead, polyimide, benzocyclobutene, spin-on glass, or the like is applied to form a flattened film. Is also good. For example, as shown in FIG. 8, a planarizing film 118 is formed, a contact hole mask is formed on each electrode, and the planarizing film 11 is formed.
8 is processed by dry etching to form a contact hole, and then wiring is drawn out from each electrode to form a flattening film 11.
The transmission line 14 may be formed on the transmission line 8. In this case, since a contact hole mask is formed on the flattening film 118, photolithography of 1 μm or less can be facilitated, a fine contact hole can be formed, and the size of each device can be reduced.

In the present invention, the GaAs / AlGaAs system is used, but other semiconductors that generate negative resistance may be used. For example, when the InP / InGaAs system is used, Ga
As compared with the As / AlGaAs system, characteristics such as the efficiency of the Gunn diode at high frequencies are improved.

The first Schottky diode 12 having such a large capacitance change, the second Schottky diode 13 having a small resistance component and a small capacitance, and the Gunn diode 11 can be integrated on the same substrate, and the signal loss can be reduced. Reduction and size reduction can be achieved.

Further, by stacking an n-InGaP layer 104 serving as an etching stopper layer on the n-GaAs layer 103 serving as the low-concentration semiconductor layer on the Schottky electrode side,
It becomes possible to selectively etch and remove the laminated structure having the diode characteristic having the negative resistance,
The n-GaAs layer 103 serving as the low-concentration semiconductor layer on the Schottky electrode side of the second Schottky diode 13 is not over-etched, and the thickness of the n-GaAs layer 103 can be kept at the thickness at the time of epitaxial growth. Variations between wafers can be reduced.
Therefore, the characteristics of the second Schottky diode 13 with good reproducibility can be obtained.

Further, since the diode having the negative resistance is the Gunn diode 11, the oscillation element having small phase noise and the first and second Schottky diodes 12, 1 are provided.
3 can be integrated on the same substrate.

Further, by manufacturing the Gunn diode 11 and the first and second Schottky diodes 12 and 13 on the same substrate, the transmission line connecting the devices can be shortened, and the signal loss can be reduced. Very effective.

(Second Embodiment) Generally speaking, epitaxial growth largely affects the state of the lower layer. In the first embodiment, the material of the Gunn diode 11 is laminated on the material of the Schottky diode 12, so that the InGa that causes the crystal lattice to be distorted under the structure of the Gunn diode 11 is formed.
Many P layers and p-type GaAs exist. Moreover, since the active layer of the gun diode 11 has a low concentration and a large thickness, epitaxial growth is difficult. In particular,
When the lattice of the active layer is distorted and the number of defects increases, the carrier concentration decreases, and it becomes difficult to obtain stable characteristics of the active layer.
Such a change in the characteristics of the active layer greatly affects the oscillation frequency, efficiency, noise characteristics, and the like of the Gunn diode.

Therefore, in the second embodiment of the present invention, the structure of the Schottky diode is stacked on the structure of the Gunn diode, so that the characteristics of the active layer of the Gunn diode are stabilized and the integrated circuit of the Gunn diode and the Schottky diode is manufactured. Will be described.

In FIG. 9, a Gunn diode 21 as a diode having a negative resistance in a region A, a first Schottky diode 22 having a large capacitance change in a region B, and a region C
A second Schottky diode 23 having a small resistance component and a small capacity is provided, and a transmission line 24 is provided in a region D.

In the region A, a cathode ohmic electrode 212 made of AuGe / Ni / Au and an anode ohmic electrode 211 are provided, and a Gunn diode 21 having an n-GaAs layer 207 serving as an active layer is formed.
On the other hand, in the region B, a first Schottky having a Schottky characteristic formed by the ohmic electrode 213 made of AuGe / Ni / Au, the n-GaAs layer 207 serving as an active layer, and the conductive film 216 made of Ti / Au. Diode 2
2 are configured. In the region C, AuGe /
A second Schottky diode having a Schottky characteristic formed by a conductive film 216 made of Ti / Au on an ohmic electrode 214 made of Ni / Au and an n-GaAs layer 221 serving as a low-concentration semiconductor layer on the Schottky electrode side. 23 are configured. The periphery of the Gunn diode 21 and the first and second Schottky diodes 22 and 23 are etched to form an isolation region 230 for isolating elements. In the region D, a transmission line 24 including the conductive film 216 and Au 217 is formed.

FIGS. 10 to 14 are cross-sectional views illustrating the steps of a method for manufacturing the Gunn diode / Schottky diode integrated circuit.

As shown in FIG. 10, a high-concentration semiconductor on the anode ohmic electrode side for a gun diode is formed on a semi-insulating GaAs substrate 201 by MBE (molecular beam epitaxy) or MOCVD (metal organic chemical vapor deposition). N ⁺ -GaAs layer 205 (Si doping concentration 5 × 10 ¹⁸
cm ⁻³ , thickness 500 nm), and an n-InGaP layer 206 (Si doping concentration 3 × 10 ¹⁸ c) serving as an etching stopper layer
m ⁻³ , thickness 20 nm), n-GaAs layer 207 serving as an active layer
(Si doping concentration 2 × 10 ¹⁶ cm ^-3 , thickness 2000n
m), n-Al _x Ga _{1 -x} As layer 208 (X = 0.35, Si doping concentration 5 × 10 ¹⁷ cm ⁻³ , thickness 50 nm) serving as a cathode layer composed of a wide band gap layer, n-Al _x Ga
_1-x As layer 209 (X = 0.35 → 0, Si doping concentration 5
× 10 ¹⁷ cm ⁻³ , thickness 20 nm), and n ⁺ to be a cathode ohmic electrode side high concentration semiconductor layer (and an ohmic electrode side high concentration semiconductor layer for the second Schottky diode 23).
-GaAs layer 210 (Si doping concentration 5 × 10 ¹⁸ cm ⁻³ ,
N-In thickness serving as an etching stopper layer
GaP layer 204 (Si doping concentration 5 × 10 ¹⁸ cm ^{- 3,} thickness 20nm), n-GaAs layer 221 serving as a Schottky electrode side low-concentration semiconductor layer (Si doping concentration 1 × 10 ¹⁷ c
m ⁻³ , thickness 150 nm).

Thereafter, as shown in FIG. 11, the region to be the second Schottky diode 22 is masked with a photoresist pattern or the like, and the n-GaAs layer 221 is selectively etched until the n-InGaP layer 204 is exposed. To remove. Next, the n-InGaP layer 204 is removed by etching using hydrochloric acid, thereby exposing the n ⁺ -GaAs layer 210 serving as the cathode ohmic electrode side high concentration semiconductor layer. At this time, the n-InGaP layer 204 is used as an etching stopper layer, but an AlGaAs layer may be used as an etching stopper layer.

Next, the cathode region of the Gunn diode 21 (shown in FIG. 9) and the second Schottky diode 22 (FIG. 9)
Is masked with a SiN film 219, and n-GaAs is formed.
Until the layer 207 is exposed, the n ⁺ -GaAs layer 210, n-Al _x G
The a _1-x As layer 209 and the n-Al _x Ga _1-x As layer 208 are removed by etching. Next, the SiN film mask 21
9 and the second Schottky diode 2 in the area B while leaving 9
The Schottky electrode region for 3 (shown in FIG. 9) is masked with a resist mask 220, and the n-GaAs layer 207 is removed by etching. Subsequently, the n-InGaP layer 206 is selectively etched and removed, exposing the n ⁺ -GaAs layer 205.

Next, as shown in FIG. 12, a part of the gun diode 21 (shown in FIG. 9) in the area A, a part of the first Schottky diode 22 (shown in FIG. 9) in the area B, and a part of the area C The second Schottky diode 23 (shown in FIG. 9) is patterned to form a resist mask (not shown) so as to isolate the element, and the n ⁺ -GaAs layer 20 is formed.
5 is etched to separate mesas.

Next, as shown in FIG. 13, the anode ohmic electrode forming region and the cathode ohmic electrode forming region of the gun diode 21 in the region A, the ohmic electrode forming region of the first Schottky diode 22 in the region B, and the region AuGe (100 n) is formed on the ohmic electrode formation region of the second Schottky diode 23 of C by vapor deposition or the like.
m) / Ni (15 nm) / Au (100 nm) to form 39
The ohmic electrode is alloyed by heat treatment at 0 ° C. By doing so, the anode ohmic electrode 2
11, cathode ohmic electrode 212, ohmic electrode 2
13 and an ohmic electrode 214 are formed. afterwards,
A silicon nitride film (not shown) serving as a protective film is
m.

Next, as shown in FIG.
Transmission lines (wirings) at steps (21, 22, 23 shown in FIG. 9)
The resist is left by a resist patterning in a place where the resist passes, and then heat treatment is performed at a temperature at which the resist is softened to cause reflow, thereby forming a resist 215 covering the step. The resist 215 prevents the transmission line from breaking at the step.

Next, as shown in FIG. 9, the n-GaAs layer 207 serving as an active layer of the first Schottky diode 22 in the region B is formed on the anode ohmic electrode 211 and the cathode ohmic electrode 212 of the gun diode 21 in the region A.
Electrode forming region and ohmic electrode 21
3, contact holes (not shown) are respectively formed in the ohmic electrode 214 of the second Schottky diode 23 in the region C and the Schottky electrode formation region on the n-GaAs layer 221 to be the Schottky electrode side low-concentration semiconductor layer. Form. Thereafter, Ti (100 n) is formed on the entire surface of the substrate by vapor deposition or the like.
m) / Au (100 nm) of a conductive film 216 is deposited. This conductive film 216 is used not only as a power supply metal for forming the transmission line 24 (wiring) thereafter by plating, but also as a Schottky electrode. At this time, the power supply metal for forming the Schottky electrode and the transmission line 24 by plating is formed at the same time. However, the Schottky electrode may be formed after the formation of the ohmic electrode of the Schottky diode. In this case, a high melting point metal such as Ti, W or Mo, a high melting point nitride, a high melting point silicide or Al can be used as a Schottky electrode material, but a material which can form a stable Schottky barrier can be used. Is desirable.

Next, a resist having a thickness of 15 μm is applied, and after patterning a region to be the transmission line 24, Au plating is performed to a thickness of 9 μm. After that, the resist is removed, unnecessary portions of the conductive film 216 are removed by etching, the reflowed resist 214 is removed, and the transmission line 24 is formed.

The first Schottky diode 22 having such a large capacitance change, the second Schottky diode 23 having a small resistance component and a small capacitance, and the Gunn diode 21 can be integrated on the same substrate. Reduction and size reduction can be achieved.

Further, by stacking an n-InGaP layer 204 serving as an etching stopper layer under the n-GaAs layer 221 serving as a Schottky electrode-side low-concentration semiconductor layer, an n- InGaAs layer serving as a Schottky electrode-side low-concentration semiconductor layer is formed. GaAs layer 22
1 can be selectively etched and removed, so that the laminated structure having the negative resistance diode characteristic is not over-etched, and the active layer of the laminated structure having the negative resistance diode characteristic becomes n-GaAs. The thickness of the layer 207 during epitaxial growth can be kept as it is, and variation between wafers can be reduced. Thereby, characteristics of a diode having a negative resistance with good reproducibility can be obtained.

Further, since the diode having the negative resistance is the Gunn diode 21, the oscillation element having low phase noise and the first and second Schottky diodes 22, 2 are provided.
3 can be integrated on the same substrate.

Further, by forming the Gunn diode 21 and the first and second Schottky diodes 22 and 23 on the same substrate, the transmission line connecting the devices can be shortened, and the signal loss can be reduced. Very effective.

(Third Embodiment) FIG. 15 is a diagram showing an equivalent circuit of a voltage controlled oscillator using a semiconductor device according to a third embodiment of the present invention. For the voltage controlled oscillator (hereinafter referred to as VCO), a Gunn diode and a Schottky diode manufactured on the same substrate in the semiconductor devices of the first and second embodiments are used.

In the VCO, an oscillation element 601 using a Gunn diode (region A in FIG. 1 or FIG. 9) and a varactor diode 602 using a second Schottky diode (region B in FIG. 1 or FIG. 9) A λ / 4 length stub 604 using the transmission line (region D in FIG. 1 or FIG. 9) as a resonator, and a λ / 4 length stub 603 using the transmission line (region D in FIGS. 1 and 9) as ground. And One end of the oscillation element 601 is connected to the ground, and the other end of the oscillation element 601 is connected to a Gunn diode bias circuit (not shown).
Connected to The other end of the oscillation element 601 is connected to one end of a λ / 4 long stub 604, and the other end of the λ / 4 long stub 604 is connected to one end of a varactor diode 602. A varactor bias circuit (not shown) is connected to the other end of the varactor diode 602,
One end of the / 4 stub 603 is connected. RF (radio frequency) is output from a connection point between the oscillation element 601 and the λ / 4 long stub 604.

In the millimeter wave band (30 GHz to 90 GHz),
If a Gunn diode and a Schottky diode are manufactured on different wafers and mounted to form a VCO, the loss in the transmission line and the loss during mounting (wire bond loss, etc.) increase, the Q value decreases, and the phase decreases. This leads to performance degradation such as poor noise. Therefore, manufacturing a Gunn diode and a Schottky diode, which are oscillation elements, on the same substrate to shorten the transmission line between devices is very effective in reducing signal loss and miniaturizing.

At this time, the varactor diode 60
The capacitance of No. 2 can also be changed by the device area of the first Schottky diode. For example, the Schottky junction capacitance of the first and second embodiments has a device area of 50 μm.
It is about 30 fF when no bias is applied at m ² , and the capacitance can be further reduced by extending the depletion layer by applying a bias. Therefore, when the area is increased, the capacitance is also increased in proportion to the area. The varactor diode 6
In No. 02, the capacitance value used in a necessary frequency band can be selected by changing the impurity concentration and the film thickness of the n-GaAs layer.

Further, when it is necessary to increase the Q value of the VCO, it is effective to provide a dielectric resonator on the substrate. However, since the VCO is conventionally formed as a hybrid type, the dielectric resonator is separately manufactured. The body resonator was mounted. In such a method, there is a problem that if the accuracy at the time of mounting the dielectric resonator is poor, the coupling of the electromagnetic fields is deteriorated, and a sufficient effect cannot be obtained. Particularly in the millimeter-wave band, high accuracy is required because the wavelength is short. On the other hand, in the third embodiment, since the wafer is monolithically formed, a dielectric resonator can be formed on each chip with high accuracy at the same time, and variations in characteristics between the chips are reduced. Specifically, after forming the transmission line, the dielectric is sputtered,
The dielectric is deposited by a method such as vapor deposition, or the sol-gel dielectric is spin-coated,
It is formed on the entire surface of the wafer. Thereafter, an etching mask is formed using photolithography using a resist or the like, and unnecessary dielectrics are removed by etching, whereby a dielectric resonator can be manufactured. Since the manufacturing accuracy of the etching mask by the photolithography can be made 1 μm or less, the distance between the dielectric resonator and the transmission line can be controlled accurately.

Further, according to the VCO of the third embodiment, in addition to the loss reduction and the downsizing, there is obtained an advantage that the oscillation frequency is stabilized when mounted on the package. Details will be described with reference to FIG. FIG. 16A shows an example in which the VCO chip 911 of this embodiment is mounted on a certain package. This package includes an alumina member 912 having a concave portion laminated on a metal ground 910.
, An alumina member 913 forming a side wall, and a lid 915. The VCO chip 911 is accommodated in the recess of the alumina member 912, and the transmission line of the VCO chip 911 is provided.
(Not shown) and a transmission line (not shown) formed on the upper surface of the alumina member 912 are connected by an Au wire 914. On the other hand, FIG. 16B shows a conventional example in which a Gunn diode 916 and a Schottky diode 917 are mounted as separate chips on the same type of package. In this conventional example, the Gunn diode 916 is housed in the recess of the alumina member 912, but the Schottky diode 917 is mounted on the upper surface of the alumina member 912. Therefore, the height of the alumina member 913B in FIG. 16B is higher than that in FIG. 16A. Thus, FIG.
In the mounting form shown in FIG. 9A, since it is not necessary to mount a chip-shaped element on the upper surface of the alumina member 912, the height h of the alumina member 913 of the package can be reduced accordingly.

This difference in package height causes a difference in stray capacitance in the package. If the stray capacitance is large, unnecessary oscillation occurs in the package or oscillation of the VCO stops. Therefore, it is very important to keep the height h of the package low. In particular, a VCO in the millimeter-wave band has a high oscillation frequency, and thus tends to easily generate oscillation lower than a required oscillation frequency. Therefore, FIG.
It can be said that the VCO using the mounting form (a) is suitable for the millimeter wave band.

FIG. 17A is a block diagram of a transmitter as a millimeter-wave band communication device using the VCO.
(b) is a configuration diagram of a receiver as a millimeter-wave band communication device using the VCO.

The transmitter shown in FIG.
In addition, a mixer 902, a filter 903, a power amplifier 904, and an antenna 905 are provided. The output terminal of the oscillator 901 is connected to the input terminal of the mixer 902, and the output terminal of the mixer 902 is connected to one end of the filter 903. The input of the power amplifier 904 is connected to the other end of the filter 903, and the antenna 905 is connected to the output terminal of the power amplifier 904.

The receiver shown in FIG. 17B has a mixer 902 and a filter 903 in addition to the oscillator 901.
, A low-noise amplifier 906, and an antenna 905. The antenna 905 has a low noise amplifier 906
, And one end of the filter 903 is connected to the output terminal of the low noise amplifier 906. One input terminal of the mixer 902 is connected to the other end of the filter 903, and the oscillator 901 is connected to the other input terminal of the mixer 902.
Output terminals are connected.

The transmitter and the receiver use the VCO configured in the third embodiment, and the oscillator 901 uses the VCO shown in FIG.
CO is used, a transmission line (region D in FIG. 1 or 9) is used for the filter 903, and a second Schottky diode (region B in FIG. 1 or 9) is used for the mixer 902. In order to obtain good characteristics with the mixer 902, a second Schottky diode having a small resistance and a small capacity is required. However, as in the first and second embodiments, the second Schottky diode is dedicated to the upper or lower layer of the epitaxial structure of the Gunn diode. It can be easily manufactured by providing the above layer. If the active layer of the Gunn diode is used, it is necessary to make the active layer thinner by etching, so that control becomes extremely difficult and a second Schottky diode having a large capacitance change is obtained. Will be gone.

As described above, in the transmitter and the receiver, Schottky diodes having different characteristics can be easily manufactured, so that a circuit having an oscillator function and a mixer function can be integrated on the same substrate. The power amplifier 9
04, it is necessary to separately mount a transistor in the low-noise amplifier 906. However, if the local signal from the oscillator 901 is sufficiently large, the power amplifier 904 and the low-noise amplifier 906 are not necessary, and the transmitter and the receiver in the millimeter wave band are used. Can be monolithic. Also, in the millimeter wave band, if the loss of the transmission line between the oscillator 901 and the mixer 902 is large, the mixer 902 cannot operate as a large signal. By manufacturing a diode and a Schottky diode constituting a mixer on the same substrate to shorten a transmission line between devices, it is very effective in reducing a signal loss.

In the first to third embodiments, the Gunn diode is used as the negative resistance diode. However, a negative resistance diode such as a tunnel diode or an impatt diode may be used.

[0088]

As is apparent from the above, according to the semiconductor device and the method of manufacturing the same of the present invention, the semiconductor device has a negative resistance which is an oscillation element having a large high-frequency power and a low phase noise without using a complicated process. The diode, the first Schottky diode having a large capacitance change, and the second Schottky diode having a small resistance component and a small capacitance can be easily integrated on the same substrate.

Further, according to the millimeter wave band communication device of the present invention, it is possible to reduce the signal loss and reduce the size, and to realize a high performance millimeter wave band communication device.

[Brief description of the drawings]

FIG. 1 is a sectional view of a Gunn diode / Schottky diode integrated circuit as a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating one step of a manufacturing process of the semiconductor device.

FIG. 3 is a sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 2;

FIG. 4 is a cross-sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 3;

FIG. 5 is a sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 4;

FIG. 6 is a sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 5;

FIG. 7 is a cross-sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 6;

FIG. 8 is a cross-sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 7;

FIG. 9 is a sectional view of a Gunn diode / Schottky diode integrated circuit as a semiconductor device according to a second embodiment of the present invention.

FIG. 10 is a cross-sectional view illustrating one step of a manufacturing process of the semiconductor device.

FIG. 11 is a sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 10;

FIG. 12 is a cross-sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 11;

FIG. 13 is a sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 12;

FIG. 14 is a sectional view illustrating one step of the manufacturing process of the semiconductor device following FIG. 13;

FIG. 15 is a diagram showing an equivalent circuit of a VCO using a semiconductor device according to a third embodiment of the present invention.

FIG. 16A is a cross-sectional view in which the VCO is mounted on a package, and FIG. 16B is a cross-sectional view in which the VCO is mounted on a package in a hybrid configuration.

FIG. 17A is a configuration diagram of a transmitter using the VCO, and FIG. 17B is a configuration diagram of a receiver using the VCO.

FIG. 18 is a cross-sectional view illustrating a conventional semiconductor device.

[Explanation of symbols]

11,21 ... Gunn diode, 12,22 ... First Schottky diode, 13,23 ... Second Schottky diode, 14,24 ... Transmission line, 101 ... Semi-insulating GaAs substrate, 102 ... n ⁺ -GaAs layer, 103 ... n-GaAs layer, 104 ... n-InGaP layer, 105 ... n ⁺ -GaAs layer, 106 ... n-InGaP layer, 107 ... n-GaAs _{layer, 108 ... n-Al x Ga} 1-x As layer, 109 ... n-Al _x Ga _{1 -x} As layer, 110 ... n ⁺ -GaAs layer, 111 ... anode ohmic electrode, 112 ... cathode ohmic electrode, 113 ... ohmic electrode, 114 ... ohmic electrode, 115 ... resist, 116 ... conductivity Film: 117: transmission line, 118: flattening film, 119: SiN film, 120: resist mask, 121: n-GaAs layer, 130: isolation region, 201: semi-insulating GaAs substrate, 04 ... n-InGaP layer, 205 ... n ⁺ -GaAs layer, 206 ... n-InGaP layer, 207 ... n-GaAs _{layer, 208 ... n-Al x Ga} 1-x As _{layer, 209 ... n-Al x Ga} 1 _-x As layer, 210 ... n ⁺ -GaAs layer, 211 ... anode ohmic electrode, 212 ... cathode ohmic electrode, 213 ... ohmic electrode, 214 ... ohmic electrode, 215 ... resist, 216 ... conductive film, 217 ... Au, 221 ... n-GaAs layer, 230 ... isolation region, 601 ... oscillation element, 602 ... varactor diode, 603 ... λ / 4 length stub, 604 ... λ / 4 length stub, 801 ... semi-insulating GaAs substrate, 802 ... n ⁺ - GaAs layer, 803 n-GaAs layer, 804 p-GaAs layer, 805 p ⁺ -GaAs layer, 806 TiW, 807 Au, 808 Ti, 809 Au, 810 Ti, 811 Au, 9 01: oscillator, 902: mixer, 903: filter, 904: power amplifier, 905: antenna, 906: low noise amplifier, 910: metal ground, 911: VCO, 912, 913, 913B: alumina member, 914: Au wire, 915 ... lid, 916 ... Gunn diode, 917 ... Schottky diode.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4M104 AA05 BB02 BB11 BB14 BB16 BB18 CC03 DD52 FF13 GG03 GG13 5F038 AV04 AZ01 BG02 DF01 EZ02 EZ14 EZ15 EZ17 EZ20

Claims (10)

[Claims] 1. A laminated structure having a Schottky diode characteristic formed by epitaxial growth on a semi-insulating substrate, wherein at least an ohmic electrode side high concentration semiconductor layer and a Schottky electrode side low concentration semiconductor layer are sequentially laminated. A laminated structure having a negative resistance diode characteristic formed by epitaxial growth on a laminated structure having a key diode characteristic, wherein the anode ohmic electrode is provided in the laminated structure having the negative resistance diode characteristic. And a diode having a negative resistance in which a cathode ohmic electrode is formed; and a Schottky diode provided in an area other than the formation area of the diode having the negative resistance, on the active layer having a stacked structure having the negative resistance diode characteristic. A first Schottky diode having electrodes formed thereon; A shot is formed on the Schottky electrode side low-concentration semiconductor layer of the stacked structure having the Schottky diode characteristic, provided in a region other than the formation region of the diode having the negative resistance and the formation region of the first Schottky diode. A semiconductor device comprising: a key electrode; and a second Schottky diode having an ohmic electrode formed on the ohmic electrode-side high-concentration semiconductor layer. 2. A laminated structure having a negative resistance diode characteristic formed by epitaxial growth on a semi-insulating substrate; and a multilayer structure formed by epitaxial growth on the laminated structure having the negative resistance diode characteristic and having at least an ohmic electrode side high concentration. A semiconductor device comprising: a stacked structure having a Schottky diode characteristic in which a semiconductor layer and a Schottky electrode-side low-concentration semiconductor layer are sequentially stacked; A diode having a negative resistance in which an electrode and a cathode ohmic electrode are formed, and a shot provided on an active layer having a stacked structure having a negative resistance diode characteristic provided in a region other than a region where the diode having a negative resistance is formed. A first Schottky diode having a key electrode formed thereon, The Schottky electrode is provided in a region other than the formation region of the diode having the negative resistance and the formation region of the first Schottky diode, and is formed on the low concentration semiconductor layer on the Schottky electrode side of the stacked structure having the Schottky diode characteristic. And a second Schottky diode having an electrode formed thereon and an ohmic electrode formed on the ohmic electrode-side high-concentration semiconductor layer. 3. The semiconductor device according to claim 1, wherein an etching stop layer is laminated on the Schottky electrode-side low-concentration semiconductor layer. 4. The semiconductor device according to claim 2, wherein an etching stop layer is laminated below the low-concentration semiconductor layer on the Schottky electrode side. 5. The semiconductor device according to claim 1, wherein the diode having a negative resistance is a Gunn diode. 6. The semiconductor device according to claim 1, wherein at least two of the diode having the negative resistance, the first Schottky diode, and the second Schottky diode are connected by a transmission line. A semiconductor device. 7. The method according to claim 1, wherein at least an ohmic electrode-side high-concentration semiconductor layer and a Schottky electrode-side low-concentration semiconductor layer are sequentially laminated on a semi-insulating substrate. A step of forming a stacked structure having key diode characteristics by epitaxial growth, and, on the stacked structure having the Schottky diode characteristics, at least an anode ohmic electrode side high concentration semiconductor layer, an active layer and a cathode ohmic electrode side high concentration semiconductor layer are sequentially formed. Forming a stacked structure having a negative resistance diode characteristic by epitaxial growth, a diode region having a negative resistance by selectively etching the stacked structure having the negative resistance diode characteristic, and a first Schottky. Forming a diode region; Forming a second Schottky diode region by selectively etching the stacked structure having the Schottky diode characteristics in a region other than the diode region having resistance and the first Schottky diode region; Forming a diode region having resistance and an isolation region separating the first Schottky diode region and the second Schottky diode region; and forming an anode ohmic electrode and a cathode ohmic electrode in the diode region having negative resistance. Forming an ohmic electrode in the first and second Schottky diode regions; forming a Schottky electrode in the first and second Schottky diode regions; and a diode region having the negative resistance. Of the anode Forming a transmission line connecting at least two of the first electrode, the ohmic electrode of the first Schottky diode region, the ohmic electrode of the first Schottky diode region, and the ohmic electrode of the second Schottky diode region; And a method for manufacturing a semiconductor device. 8. The method for manufacturing a semiconductor device according to claim 2, wherein at least an anode ohmic electrode-side high-concentration semiconductor layer, an active layer, and a cathode ohmic electrode-side high-concentration semiconductor layer are sequentially formed on a semi-insulating substrate. Forming a laminated structure having a stacked negative resistance diode characteristic by epitaxial growth; and forming at least an ohmic electrode side high concentration semiconductor layer and a Schottky electrode side low concentration semiconductor layer on the stacked structure having the negative resistance diode characteristic. Forming, by epitaxial growth, a stacked structure having Schottky diode characteristics in which is sequentially stacked; and forming a second Schottky diode region by selectively etching the stacked structure having the Schottky diode characteristics; Laminated structure having the above negative resistance diode characteristics Forming the diode region having the negative resistance and the first Schottky diode region by selectively etching; the diode region having the negative resistance, the first Schottky diode region, and the second Schottky Forming an isolation region for separating the diode region; forming an anode ohmic electrode and a cathode ohmic electrode in the diode region having negative resistance; and forming ohmic electrodes in the first and second Schottky diode regions. Forming a Schottky electrode in the first and second Schottky diode regions; an anode ohmic electrode and a cathode ohmic electrode in the diode region having the negative resistance; and an ohmic electrode in the first Schottky diode region. ,shot Forming a transmission line connecting at least two of the key electrode, the ohmic electrode in the second Schottky diode region, and the Schottky electrode. 9. A millimeter-wave band communication device using the semiconductor device according to claim 6, wherein the diode having the negative resistance is used as an oscillation element, and the transmission line is used as an open stub or a short stub. A millimeter wave band communication device, wherein the first Schottky diode is used as a varactor diode, and the second Schottky diode is used as a mixer. 10. The millimeter wave band communication device according to claim 9, wherein the diode having the negative resistance is a Gunn diode.