JP2005123385A - Semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor device that can be suppressed in the variation of its characteristics in a band from a microwave band to a tera-hertz band, can be mounted easily, and can efficiently transmit high-frequency signals to a space or external circuit. <P>SOLUTION: The semiconductor device 100 is provided with a substrate 1 having an n-type semiconductor layer 2A having a projecting stripe section 18 in its uppermost part; a signal line 5 which is formed on the substrate 1 and extended to pass through the upside of the projecting stripe section 18 of the n-type semiconductor layer 2A; and a grounding conductor 6 which is formed on the substrate 1, disposed separately from the signal line 5, and constitutes a transmission line together with the signal line 5. The device 100 is also provided with an oscillation element 15 constituted of the n-type semiconductor layer 2A, signal line 5, and grounding conductor 6; and a high-frequency utilizing circuit section 11 which is formed on the substrate 1 and connected to the signal line 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a semiconductor device that operates in a microwave band, a millimeter wave band, and a terahertz frequency band.

  In recent years, technological progress in the information communication field has been remarkable, and the frequency band handled by communication equipment has also changed from a microwave band to a millimeter wave band to a higher frequency band. In such a communication circuit that handles a high frequency band from the microwave band to the millimeter wave band, an oscillation circuit or an oscillation element that generates a high frequency signal is an important circuit element. Conventionally, for the generation of a high-frequency signal in the microwave band, an oscillation circuit in which a positive feedback is applied to a high-frequency amplifier or a two-terminal element whose element itself has a negative resistance characteristic is used. Of these, the output of the oscillation circuit that applies positive feedback to the high-frequency amplifier may not be sufficient because the frequency characteristics of the high-frequency amplifier deteriorate from the millimeter wave band to the high-frequency band. For this reason, two-terminal elements exhibiting negative resistance characteristics are frequently used at frequencies above the millimeter wave band.

  Typical examples of the two-terminal element exhibiting negative resistance characteristics include a Gunn diode using a gun effect, an IMPATT diode using an avalanche phenomenon of electrons, and a tunnel diode using negative resistance characteristics. Among them, the Gunn diode is useful because it has a relatively simple structure and a relatively large output.

  A Gunn diode is a diode that utilizes the Gunn effect. The gun effect is a state in which the mobility is high when the traveling speed of electrons has an electric field dependency and the electric field strength is smaller than the critical value Eth in a direct transition type n-type semiconductor having a zinc flash structure. On the other hand, when the electric field strength becomes larger than the critical value Eth, this is an effect that occurs because the mobility shifts to a low state. Here, the principle of generating the gun effect will be described with reference to FIGS. FIG. 14 is a diagram schematically showing the principle that a gun effect occurs in a planar type Gunn diode, and FIG. 15 shows the relationship between electric field strength and electron traveling speed in a Gunn diode using n-type GaAs. It is a figure (refer nonpatent literature 1). In FIG. 15, the horizontal axis represents the electric field strength, and the vertical axis represents the traveling speed of electrons.

  As shown in FIG. 14, the planar type Gunn diode includes an n-type semiconductor layer 102 that is formed on the uppermost portion of the substrate 101 and generates the above-described gun effect, and a pair of electrodes 103 that are formed on the n-type semiconductor layer 102. It consists of. In this Gunn diode, when an electric field larger than Eth is applied from the pair of electrodes 103 to the n-type semiconductor layer 102 that produces the above-described Gunn effect, the dependence of the traveling speed of electrons on the electric field strength (see FIG. 15). Distribution) occurs in the traveling speed of electrons in the n-type semiconductor layer 102. As a result, an electric field distribution is generated in the n-type semiconductor layer 102, and a region (domain) 104 with a high electron concentration is generated in the n-type semiconductor layer 102. When the domain 104 reaches one electrode 103, a current peak is generated, and this domain 104 is repeatedly generated and travels. As a result, a high-frequency signal is generated according to the period in which the domain 104 reaches one electrode 103. Note that the velocity Vd (cm / s) of the domain 104 coincides with the traveling velocity of electrons saturated at a sufficiently large electric field strength.

  There are several modes for forming the domain 104, and a typical one is a dipole mode in which the domain 104 is generated in one place in the n-type semiconductor layer 102. The maximum frequency f0 of the high-frequency signal generated in the dipole mode is determined by the distance L (cm) between the electrodes 103 and the domain moving speed Vd (cm / s), and is represented by the following formula (1).

  f0 = Vd / L (Hz) (1)

  Furthermore, in the gun effect, there is a higher-order mode (hybrid mode) in which a plurality of domains 104 are simultaneously generated. It has been estimated that the frequency f of the high frequency signal generated in the hybrid mode is experimentally represented by the following expression (2).

  f0 <f <(50 × f0) (2)

Further, as a distance L (cm) between the impurity concentration N ₀ (cm ⁻³ ) of the n-type semiconductor layer 102 and the electrode 103, satisfying the following formula (3) is a condition for generating a gun effect (non-contained) (See Patent Document 1).

N ₀ L> 10 ¹² (cm ⁻² ) (3)

  The condition shown in Equation (3) is indicated by the shaded area in FIG. FIG. 16 is a diagram illustrating conditions under which the cancer effect occurs.

  It is possible to estimate the doping concentration of the impurity causing the gun effect with respect to the distance L between the electrode 103 and FIG.

  Further, the condition for generating the gun effect in the hybrid mode is expressed by the following formula (4) on the premise that a higher electric field is applied than in the dipole mode.

5 × 10 ¹³ > N ₀ L> 10 ¹² (cm ⁻² ) (4)

The normal processing upper limit of the convex shape by the thin film deposition method or etching is about 10 μm. Assuming a Gunn diode that flows current in the convex film thickness direction, the range in which the Gunn effect occurs in the hybrid mode in consideration of the condition shown in Expression (4) is indicated by a region R in FIG. Further, since the impurity concentration N ₀ of the n-type semiconductor layer 102 is usually about 1 × 10 ¹⁶ to 1 × 10 ¹⁸ (cm ⁻³ ), when the distance L between the electrodes 103 is 0.01 μm or more. It can be seen that a cancer effect occurs.

FIG. 17 shows f0 in the most basic dipole mode. From FIG. 17, it is possible to estimate the transmission frequency f0 in the dipole mode with respect to the distance L between the electrodes 3 assuming the value of the velocity Vd of the domain 104. In FIG. 17, based on the normal Vd being 1 × 10 ⁶ to 1 × 10 ⁸ (cm / s), values close to the actual saturation electron velocity (1 × 10 ⁵ , 1 × 10 ⁶ , 1 × 10 ^7). 1 × 10 ⁸ (cm / s)).

Although FIG. 17 shows the oscillation frequency f0 in the dipole mode, the maximum operating frequency f in the hybrid mode can be up to about 50 times f0, so that for example, Vd = 10 ⁷ (cm / s), L = 5 (μm), about 1 THz oscillation (f0 = 20 GHz), and Vd = 10 ⁷ (cm / s) and L = 2.5 (μm), about 3 THz oscillation ( It can be seen that f0 = 50 GHz) is possible. Furthermore, operation at a higher frequency is expected by using a material having a large Vd or by shortening L.

  Conventionally, a Gunn diode can be mounted on a cylindrical case called a pill type package as shown in Patent Document 3 below using a bulk type Gunn diode as shown in Patent Document 1 and Patent Document 2 below. Many. The pill type package is designed for a three-dimensional circuit application such as being arranged in a waveguide, and is not very suitable for planar mounting. Further, it may be necessary to bring the rod into contact with the electrode portion of the package in order to extract the high-frequency signal to the outside, which is not very suitable for integration. Furthermore, since the three-dimensional shape of the pill package is comparable to the wavelength of the terahertz band, it may be difficult to obtain a high frequency output in the terahertz band.

  On the other hand, a Gunn diode that can be flip-chip mounted as a configuration that can be mounted in a plane is shown in Patent Document 3 below. An example in which the Gunn diode is flip-chip mounted on a flat circuit board constituting a microstrip line will be described with reference to FIG.

  As shown in FIG. 18, a signal electrode 132 is formed on the surface of the semi-insulating flat substrate 131, and a ground electrode 133 is formed on the back surface. In addition, a via hole 134 is provided in the flat substrate 131 and penetrates the flat substrate 131 to connect the ground electrode 133 on the back surface and the surface ground electrode 135 formed on the front surface to each other. Filled with tungsten.

  Further, the Gunn diode 110A is mounted on the flat substrate 131 in a face-down posture, and the cathode bump and the anode bump of the Gunn diode 110A are directly connected to the signal electrode 132 and the surface ground electrode 135, respectively.

The signal electrode 132 includes a bias electrode 132A that supplies a bias voltage to the Gunn diode 110A, an electrode 132B that forms a resonator using a microstrip line including the Gunn diode 110A, and a signal output electrode 132C that forms the microstrip line. Has been.
JP-A-6-314802 (FIG. 1). Japanese Patent Laid-Open No. 7-11348 (FIG. 3). Japanese Patent Laid-Open No. 2002-134810 (FIGS. 1, 3, and 9). W. Alan Davis, Microwave Semiconductor Circuit Design, Chapter 15, Van Nostrand Reinhold Company Inc., New York 1984.

  As described above, the Gunn diode mounted on the surface is actually premised on flip chip mounting. At this time, in order to use the Gunn diode in the circuit of the terahertz band, the variation in the mounting position accuracy of the Gunn diode must be about 1/20 of the wavelength of the target frequency (300 μm at 3 THz).

  However, in flip-chip mounting, it is very difficult to mount a Gunn diode with the above-mentioned accuracy, and it is difficult to suppress variations in characteristics in the terahertz band of a product mounting the Gunn diode.

  Further, signal transmission loss is large from the millimeter wave band to the terahertz band. For this reason, it is desirable to shorten the transmission line length as much as possible. In order to shorten the transmission line length, it is necessary to make the circuit smaller and further integrate the circuit elements. However, both pill package and flip chip mounting applied to conventional Gunn diodes will require further integration. It is difficult to realize.

  The present invention has been made in view of such points, and variation in characteristics from the microwave band to the terahertz band is suppressed, mounting is easy, and high-frequency signals are efficiently transmitted to space and external circuits. An object of the present invention is to provide a semiconductor device capable of performing

A first semiconductor device of the present invention includes a substrate having an n-type semiconductor layer having a convex portion at the uppermost portion, and is formed on the substrate and extends over the convex portion of the n-type semiconductor layer. A signal line, a ground line formed on the substrate and spaced apart from the signal line, and constituting the signal line and the transmission line; the n-type semiconductor layer; the signal line and the ground line; An oscillation element comprising: a high-frequency utilization circuit unit formed on the substrate and connected to the signal line;
Is provided.

  The first semiconductor device of the present invention has a structure in which the signal line and the ground line constituting the transmission line, the oscillation element, and the high-frequency utilization circuit unit connected to the signal line are incorporated into one substrate. . That is, a semiconductor device in which the oscillation element is mounted with very high accuracy can be obtained without using flip chip mounting or the like. Therefore, in the first semiconductor device of the present invention, variation in characteristics in the terahertz band is suppressed. Further, it is not necessary to connect the oscillation element to the high frequency utilization circuit using a wire or a bump. For this reason, the transmission line length is shortened compared to the pill type package and the flip chip mounting, and the signal transmission loss can be reduced from the millimeter wave band to the terahertz band. Therefore, it is possible to efficiently transmit a high frequency signal to a space or an external circuit through the high frequency utilization circuit unit.

  The n-type semiconductor layer is preferably formed of a direct transition type compound semiconductor having a zinc flash structure, and the oscillation element is preferably a Gunn diode.

  Since the Gunn diode has a relatively simple structure and a relatively large output can be obtained, the performance of the semiconductor device can be improved.

  The n-type semiconductor layer may be formed of one type of compound semiconductor selected from the group consisting of GaAs, InP, InSb, ZnSe, and CdTe, or a mixed crystal of at least two types of compound semiconductors.

  The n-type semiconductor layer may be formed of GaInNAs.

  The high frequency utilization circuit unit may be configured by a patch antenna or a filter.

  A second semiconductor device of the present invention is formed on a top surface of a substrate having an n-type semiconductor layer having a convex portion on the top, and passes over the convex portion of the n-type semiconductor layer. A signal line extending on the lower surface of the substrate, forming a ground line forming the signal line and the transmission line, and formed on the upper surface of the substrate spaced apart from the signal line and connected to the ground line. A grounding electrode, an n-type semiconductor layer, an oscillation element composed of the signal line and the ground electrode, and a high-frequency utilization circuit unit formed on the substrate and connected to the signal line.

  In the second semiconductor device of the present invention, the signal line and the ground line constituting the transmission line, the oscillation element, and the high-frequency utilization circuit unit connected to the signal line are incorporated into one substrate. . That is, a semiconductor device in which the oscillation element is mounted with very high accuracy can be obtained without using flip chip mounting or the like. Therefore, in the second semiconductor device of the present invention, variation in characteristics in the terahertz band is suppressed. Further, it is not necessary to connect the oscillation element to the high frequency utilization circuit using a wire or a bump. For this reason, the transmission line length is shortened compared to the pill type package and the flip chip mounting, and the signal transmission loss can be reduced from the millimeter wave band to the terahertz band. Therefore, it is possible to efficiently transmit a high frequency signal to a space or an external circuit through the high frequency utilization circuit unit. In particular, in the second semiconductor device of the present invention, the signal line and the ground line constitute a microstrip transmission line. The microstrip transmission line has been sufficiently analyzed for its high-frequency characteristics, and a highly accurate model is provided for electromagnetic field simulation. Therefore, the second semiconductor device of the present invention is particularly useful when it is necessary to design a microstrip type transmission line with high accuracy.

  The n-type semiconductor layer is preferably formed of a direct transition type compound semiconductor having a zinc flash structure, and the oscillation element is preferably a Gunn diode.

  Since the Gunn diode has a relatively simple structure and a relatively large output can be obtained, the performance of the semiconductor device can be improved.

  The n-type semiconductor layer may be formed of one type of compound semiconductor selected from the group consisting of GaAs, InP, InSb, ZnSe, and CdTe, or a mixed crystal of at least two types of compound semiconductors.

  The n-type semiconductor layer may be formed of GaInNAs.

  The high frequency utilization circuit unit may be configured by a patch antenna or a filter.

  According to the present invention, it is possible to provide a semiconductor device in which variation in characteristics from a microwave band to a terahertz band is suppressed, mounting is easy, and a high-frequency signal can be efficiently transmitted to a space or an external circuit. Can do.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present specification, the term “high frequency” means a high frequency band of a microwave band or higher (about 0.8 GHz or higher).

(Embodiment 1)
FIG. 1 is a top view showing the semiconductor device of this embodiment. FIG. 2 is an enlarged view of the vicinity of the oscillation element shown in FIG. 3A, 3B, and 3C are cross-sectional views taken along lines AA, BB, and CC in FIG. 2, respectively. 4 is a perspective view of the vicinity of the oscillation element shown in FIG.

  As shown in FIGS. 1 to 4, the semiconductor device 100 of this embodiment includes a substrate 1 having an n-type semiconductor layer 2 </ b> A having a convex portion 18 at the top, and an n-type semiconductor layer formed on the substrate 1. A signal line 5 extending over the convex portion 18 of 2A, a ground line 6 formed on the substrate 1 and spaced apart from the signal line 5, and constituting the transmission line and the signal line 5, n An oscillation element 15 including a type semiconductor layer 2A, a signal line 5 and a ground line 6, and a high-frequency utilization circuit unit 11 formed on the substrate 1 and connected to the signal line 5.

  Specifically, in this embodiment, a mother substrate formed of Fe-doped semi-insulating InP is prepared, and an Si-doped InP thin film is formed on the mother substrate as an n-type semiconductor layer 2A by epitaxial growth. Is used as the substrate 1.

  The signal line 5 and the ground line 6 are directly formed on the substrate 1 using a metal thin film having a thickness of about 5 μm to form a coplanar transmission line, and are in ohmic contact with the n-type semiconductor layer 2A. In this embodiment, the ohmic contact is formed by forming AuGeNi or an AuGe alloy at the contact interface between the signal line 5 and the ground line 6 with respect to the n-type semiconductor layer 2A and performing a heat treatment at 300 ° C. In the present embodiment, the signal line 5 and the ground line 6 are plated with Au.

  The signal line 5 is connected to the bias terminal 8 through the bias line 8a to which the stub 10 is connected. That is, a DC voltage is applied to the n-type semiconductor layer 2A through the bias terminal 8 from an external power source, and the signal line 5, the ground line 6, and the n-type semiconductor layer 2A provided at one end of the signal line 5. The oscillating element 15 configured as is a Gunn diode.

  Furthermore, the other end of the signal line 5 is connected to a patch antenna formed of a metal thin film as the high-frequency utilization circuit 11 so that the high-frequency power generated by the oscillation element 15 is radiated to the space. The shape of the patch antenna 11 can be changed as appropriate according to the operating frequency band.

  The ground line 6 is grounded through the ground terminal 7. Also, in the portion of the ground line 6 where the signal line 5 and the ground line 6 constitute a transmission line, the ground line 6 is placed across the signal line 5 in order to make the ground potential of the transmission line the same. An air bridge 9 made of Au wiring to be connected is formed.

  Here, the oscillation element 15 will be further described with reference to FIGS.

In the present embodiment, the oscillation element 15 includes an n-type semiconductor layer 2A formed on the uppermost portion of the substrate 1, a signal line 5, and a signal line 5, as shown in FIGS. 2, 3A to 3C, and FIG. , A Gunn diode composed of a ground line 6 provided apart from the signal line 5. In particular, in this embodiment, the n-type semiconductor layer 2A includes an n-semiconductor layer 2 having a concentration of Si as an n-type impurity of 1 × 10 ¹⁷ (cm ⁻³ ) and a film thickness of about 0.5 μm, and n The n + semiconductor layers 12a and 12b are formed above and below the semiconductor layer 2 and the n-type impurity concentration is higher than that of the n− semiconductor layer 2 (the concentration of Si as an impurity is 1 × 10 ¹⁹ (cm ⁻³ )). It is configured. Note that the n + semiconductor layers 12a and 12b as the contact layers are not necessarily required. As shown in FIG. 3C, the n− semiconductor layer 2 and the n + semiconductor layer 12 a formed thereon form a convex portion 18.

  Furthermore, the signal line 5 and the ground line 6 are formed directly on the substrate 1, but the signal line 5 is positioned on the n + semiconductor layer 12a particularly in the region where the n-type semiconductor layer 2A is formed. The ground line 6 is formed so as to be located on the n + semiconductor layer 12b.

  Further, as shown in FIGS. 3A and 4, an air bridge made of Au wiring connecting the ground line 6 across the signal line 5 in order to make the ground potential of the coplanar transmission line the same near the oscillation element 15. 9 is formed.

  Here, the operation of the oscillation element 15 will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing the operation of the oscillation element 15.

  In the oscillation element 15, when the bias voltage applied to the signal line 5 through the bias terminal 8 is a positive voltage, the upper surface of the n − semiconductor layer 2 is substantially equipotential with the signal line 5, and the lower surface of the n − semiconductor layer 2 is The ground line 6 is almost equipotential, and an electric field perpendicular to the n− semiconductor layer 2 is generated in the n− semiconductor layer 2. Accordingly, as shown in FIG. 5, the domain 4 that moves from the n + semiconductor layer 12 b toward the n + semiconductor layer 12 a is formed in the n− semiconductor layer 2. That is, the oscillation element 15 functions as a Gunn diode.

  The oscillation frequency of the oscillation element 15 is determined by the thickness L of the n − semiconductor layer 2 and is 0.5 μm here. However, this is one of the design matters, and it may be appropriately designed so as to obtain a desired oscillation frequency between 0.1 to 10 μm.

  Here, the results of examining the characteristics of the oscillation element 15 and the semiconductor device 100 of the present embodiment will be described.

  The oscillation element (Gun diode) 15 of the present embodiment exhibited high-frequency oscillation characteristics in an electric field larger than the threshold electric field Eth. Further, the oscillation frequency was larger than the value calculated as a simple dipole mode when the thickness L of the n− semiconductor layer 2 was 5 μm or less. Further, the oscillation frequency slightly changes depending on the DC voltage value applied to the bias terminal 8 of the semiconductor device 100, and the oscillation frequency can be adjusted. At this time, it was confirmed that the electric field is radiated from the patch antenna to the space in the semiconductor device 100.

  Conventionally, as described above, an oscillation element such as a Gunn diode is mounted by flip-chip mounting or the like, and in order to use the Gunn diode in a terahertz band circuit, tolerance of accuracy variation when mounting the Gunn diode is allowed. The range is comparable to the wavelength of the target frequency (300 μm at 3 THz). However, in flip chip mounting, it is very difficult to mount a Gunn diode with the above accuracy, and it is difficult to suppress variations in characteristics in the terahertz band of a product mounted with a Gunn diode.

  In the semiconductor device 100 of the present embodiment, the signal line 5 and the ground line 6 that constitute the transmission line, the oscillation element 15, and the high-frequency utilization circuit unit (patch antenna in the present embodiment) 11 connected to the signal line 5 are provided. It is structured to be incorporated in one substrate. That is, in the semiconductor device 100, the oscillation element 15 is mounted with the above accuracy without using flip-chip mounting or the like. Therefore, in the semiconductor device 100 of this embodiment, variation in characteristics in the terahertz band or the like is suppressed.

  Further, as described above, it is difficult to realize further integration in both the pill type package and the flip chip mounting applied to the conventional Gunn diode. In particular, in order to connect the oscillation element to the transmission line at the time of flip-chip mounting, it becomes necessary to connect using a wire or a bump.

  On the other hand, in the semiconductor device 100 of the present embodiment, the signal line 5 and the ground line 6 that constitute the transmission line, the oscillation element 15, and the high-frequency utilization circuit unit (patch antenna in the present embodiment) 11 connected to the signal line 5. And the signal line 5 and the ground line 6 also serve as the electrodes of the oscillation element 15. That is, there is no need to connect using wires or bumps. For this reason, the transmission line length is shortened compared to the pill type package and the flip chip mounting, and the signal transmission loss can be reduced from the millimeter wave band to the terahertz band. Accordingly, it is possible to efficiently transmit a high frequency signal to a space or an external circuit through the high frequency utilization circuit unit 11.

  In particular, in the present embodiment, a desired oscillation frequency can be obtained by appropriately designing the thickness L of the n − semiconductor layer 2. In a general semiconductor device manufacturing process, the thickness L of the n − semiconductor layer 2 can be easily reduced, for example, compared to the distance between wirings, and the film thickness can be controlled to about 1 nanometer. Can also be realized. Therefore, it is easy to operate the oscillation element 15 at a higher frequency, and it is possible to provide a semiconductor device having a very high frequency and good controllability of the oscillation frequency.

  In the semiconductor device 100 of this embodiment, one oscillation element 15 is provided, but the present invention is not limited to this. For example, in the semiconductor device 100 of this embodiment, an oscillation element having a thickness L different from that of the n − semiconductor layer 2 can be formed at a location different from the oscillation element 15 on the substrate 1. For this reason, if the semiconductor device 100 of this embodiment is used for a communication device used in a communication method using a plurality of different frequencies or a communication device that switches a plurality of frequency bands, the communication device can be reduced in size.

  In the present embodiment, the substrate 1 is formed by epitaxially growing an n-type semiconductor layer 2A on an InP substrate. For this reason, the crystallinity of the n-type semiconductor layer 2A is almost the same as that of the single crystal material, and the effect of improving the characteristics of the oscillation element 15 is also obtained.

  Next, a method for manufacturing the semiconductor device 100 of this embodiment will be described with reference to FIGS. 6 to 8 are process cross-sectional views illustrating a method for manufacturing the oscillation element 15 of the semiconductor device 100.

First, in the step shown in FIG. ^6A , an n + semiconductor layer 12b having an n-type impurity concentration of 1 × 10 ¹⁹ (cm ⁻³ ) and an n + semiconductor layer 12b are formed on the n + semiconductor layer 12b. and n- semiconductor layer 2 is but ^{1 × 10 17 (cm -3)} , n- semiconductor layer is formed on the 2, n + semiconductor layer is an n-type impurity concentration is 1 × 10 ¹⁹ (cm ^-3) A substrate 1 having an n-type semiconductor layer 2A made of 12a at the top is prepared. Specifically, the substrate 1 is prepared by preparing a mother substrate and sequentially forming the n + semiconductor layer 12b, the n− semiconductor layer 2, and the n + semiconductor layer 12a by epitaxial growth on the mother substrate. The mother substrate may be a semiconductor substrate or a dielectric substrate.

  Next, in the step shown in FIG. 6B, a resist 20 is deposited on the n + semiconductor layer 12a.

  Next, in the step shown in FIG. 6C, the resist 20 is patterned to form an opening 21 that penetrates the resist 20 and exposes the n + semiconductor layer 12a.

  Next, in the step shown in FIG. 7A, the n + semiconductor layer 12a and the n + semiconductor layer 12a and the n + semiconductor layer 12 are patterned by performing etching using the resist 20 in which the opening 21 is formed as a mask. An opening 22 that penetrates the n− semiconductor layer 2 and exposes the n + semiconductor layer 12b is formed.

  Next, in the step shown in FIG. 7B, the resist 20 is removed to expose the surface of the n + semiconductor layer 12a and the n + semiconductor layer 12b in the opening 22.

  Next, a resist 23 is deposited on the substrate 1 in the step shown in FIG.

  Next, in the process shown in FIG. 8A, by patterning the resist 23, an opening 24a that penetrates the resist 23 and exposes the n + semiconductor layer 12a, and an opening 24b that exposes the n + semiconductor layer 12b, Form.

  Next, in the step shown in FIG. 8B, a metal thin film 25 is formed by vapor deposition on the exposed surfaces of the n + semiconductor layers 12 a and 12 b and on the resist 23. At this time, as the material of the metal thin film 25, a material that forms ohmic contact with the n + semiconductor layers 12a and 12b is used.

  Next, in the step shown in FIG. 8C, the metal thin film on the resist 23 is removed by a lift-off method, and then the resist 23 is removed. Although not shown in the figure, the metal thin film 25 is patterned at the same time as this step, so that the signal line 5, the ground line 6, the bias line 8a, the stub 10, and the high-frequency circuit section (this In the embodiment, a patch antenna 11 is formed on the substrate 1.

  Finally, the air bridge 9 that connects the ground wire 6 across the signal line 5 is used to obtain the semiconductor device 100 of the present embodiment.

  Next, in the semiconductor device 100 of the first embodiment, an example of an oscillation element that can be used in place of the above-described oscillation element 15 and has a structure different from the oscillation element 15 will be described. 9, FIG. 10 and FIG. 11 correspond to the cross-sectional views along line CC in FIG.

First, a first example of an oscillation element will be described with reference to FIG. As shown in FIG. 9, the oscillation element 15B is formed on the uppermost portion of the substrate 1, and includes an n-type semiconductor layer 2B having a convex portion 18b, a signal line 5 formed on the convex portion 18b, and an n-type semiconductor layer. It is a Gunn diode composed of a ground line 6 formed on the semiconductor layer 2B. In particular, in this example, the n-type semiconductor layer 2B has a concentration of Si, which is an n-type impurity, of 1 × 10 ¹⁷ to 1 × 10 ¹⁸ (cm ⁻³ ), and a film thickness of the convex portion is about 2.0 μm. The n − semiconductor layer 2 is formed. The convex portion 18b has a height (L in the drawing) of 0.4 μm. The n-type semiconductor layer 2B is formed by a normal photolithography technique and a general etching technique. In addition, you may set the diameter of the convex-shaped part 18b arbitrarily within the range of 2-200 micrometers.

  Here, the operation of the oscillation element 15B will be described. In the oscillation element 15B, when the bias voltage applied to the signal line 5 through the bias terminal 8 is a positive voltage, the upper surface of the convex portion 18b is substantially equipotential with the signal line 5, and the ground line 6 of the n− semiconductor layer 2 is used. Is in contact with the ground line 6, and an electric field in the thickness direction of the n − semiconductor layer 2 is generated in the convex portion 18 b. Accordingly, a domain moving from the substrate 1 toward the signal line 5 is formed in the convex portion 18b. That is, the oscillation element 15B functions as a Gunn diode.

  The oscillation frequency of the oscillation element 15B is determined by the height L of the convex portion 18b, and is 0.4 μm here. However, this is one of the design matters. Since the height L of the convex portion 18b corresponds to the etching depth of the n-type semiconductor layer 2B, the desired oscillation frequency is between about 0.1 to 1 μm. It is preferable to design appropriately so that it may be obtained.

The oscillation element 15B exhibited high-frequency oscillation characteristics in an electric field larger than the threshold electric field Eth. The oscillation frequency is higher than that calculated as a simple dipole mode when the height L of the convex portion 18b is 0.4 μm and the impurity concentration is 5 × 10 ¹⁷ (cm ⁻³ ) or less. It was a big one. In addition, when the height L of the convex portion 18b is 1 μm, oscillation in a simple dipole mode was observed in the impurity concentration range of 5 × 10 ¹⁷ to 1 × 10 ¹⁸ (cm ⁻³ ). On the other hand, the oscillation frequency slightly changes depending on the DC voltage value applied to the bias terminal 8 of the semiconductor device 100, and the oscillation frequency can be adjusted. In these operating states, it was confirmed that the electric field is radiated from the patch antenna to the space in the semiconductor device 100.

Next, a second example of the oscillation element will be described with reference to FIG. As shown in FIG. 10, the oscillation element 15C is formed on the uppermost portion of the substrate 1, and includes an n-type semiconductor layer 2C having a convex portion 18c, a signal line 5 formed on the convex portion 18c, and an n-type. This is a Gunn diode composed of a ground line 6 formed on the semiconductor layer 2C. In particular, in this example, the n-type semiconductor layer 2C has a concentration of Si, which is an n-type impurity, of 1 × 10 ¹⁷ to 1 × 10 ¹⁸ (cm ⁻³ ), and a film thickness of the convex portion is about 2.0 μm. The n− semiconductor layer 2 and the n− semiconductor layer 2 formed on the n− semiconductor layer 2 have a higher n-type impurity concentration than the n− semiconductor layer 2 (impurity Si concentration is 1 × 10 ¹⁹ (cm ⁻³ )) n + And a semiconductor layer 12c. The convex portion 18c has a height (L in the drawing) of 0.4 μm. The n-type semiconductor layer 2C is formed by a normal photolithography technique and a general etching technique. In addition, you may set arbitrarily the diameter of the convex-shaped part 18c within the range of 2-200 micrometers.

  Si, which is an impurity, is introduced into the n + semiconductor layer 12c by a thermal diffusion method. The signal line 5 and the ground line 6 are formed on the n + semiconductor layer 12.

  Here, the operation of the oscillation element 15C will be described. In the oscillation element 15C, when the bias voltage applied to the signal line 5 through the bias terminal 8 is a positive voltage, the upper surface of the n − semiconductor layer 2 in the convex portion 18c is substantially equipotential with the signal line 5, and the n − semiconductor. The contact surface of the layer 2 with the ground line 6 becomes substantially equipotential with the ground line 6, and an electric field in the thickness direction of the n − semiconductor layer 2 is generated in the convex portion 18 c. Therefore, a domain moving from the substrate 1 toward the signal line 5 is formed in the convex portion 18c. That is, the oscillation element 15C functions as a Gunn diode.

  The oscillation frequency of the oscillation element 15C is determined by the height L of the convex portion 18c, and is 0.4 μm here. However, this is one of the design matters. Since the height L of the convex portion 18c corresponds to the etching depth of the n-type semiconductor layer 2C, the desired oscillation frequency is between about 0.1 to 1 μm. It is preferable to design appropriately so that it may be obtained.

Next, a third example of the oscillation element will be described with reference to FIG. As shown in FIG. 11, the oscillation element 15D is formed on the uppermost portion of the substrate 1, and includes an n-type semiconductor layer 2C having a convex portion 18d, a signal line 5 formed on the convex portion 18d, and an n-type semiconductor layer. This is a Gunn diode composed of a ground line 6 formed on the semiconductor layer 2C. In particular, in this example, the n-type semiconductor layer 2D has a concentration of Si as an n-type impurity of 1 × 10 ¹⁷ to 1 × 10 ¹⁸ (cm ⁻³ ), and a film thickness of the convex portion is about 2.0 μm. The n− semiconductor layer 2 and the n− semiconductor layer 2 are formed, and the concentration of the n-type impurity is higher than that of the n− semiconductor layer 2 (the concentration of Si as an impurity is 1 × 10 ¹⁹ (cm ⁻³ )) n + The semiconductor region 12d is configured. The convex portion 18d has a height of 0.4 μm. Further, the distance (L shown in FIG. 11) between the lower surface of the n + semiconductor region 12d in the convex portion 18d and the lower surface of the n + semiconductor layer 12d in contact with the ground line 6 is also the height of the convex portion 18d. It is approximately the same, 0.4 μm. The n-type semiconductor layer 2C is formed by a normal photolithography technique and a general etching technique. In addition, you may set arbitrarily the diameter of the convex-shaped part 18d within the range of 2-200 micrometers.

  The n + semiconductor region 12d is formed by introducing Si as an impurity into the n− semiconductor layer 2 by ion implantation. The signal line 5 and the ground line 6 are formed so as to be located on the n + semiconductor region 12.

  Here, the operation of the oscillation element 15D will be described. In the oscillation element 15D, when the bias voltage applied to the signal line 5 through the bias terminal 8 is a positive voltage, the lower surface of the n + semiconductor region 12d in the convex portion 18d is substantially equipotential with the signal line 5, and the ground line 6 The lower surface of the n + semiconductor layer 12d in contact with the ground line 6 is almost equipotential, and an electric field in the thickness direction of the n− semiconductor layer 2 is generated in the convex portion 18d. Accordingly, a domain moving from the substrate 1 toward the signal line 5 is formed in the convex portion 18d. That is, the oscillation element 15D functions as a Gunn diode.

  The oscillation frequency of the oscillation element 15D is the distance between the height of the convex portion 18d, that is, the lower surface of the n + semiconductor region 12d in the convex portion 18d and the lower surface of the n + semiconductor layer 12d in contact with the ground line 6. L, which is 0.4 μm here. However, this is one of the design matters, and is between the height of the convex portion 18d (that is, between the lower surface of the n + semiconductor region 12d in the convex portion 18d and the lower surface of the n + semiconductor layer 12d in contact with the ground line 6). In order to correspond to the etching depth of the n-type semiconductor layer 2D, the distance L) is preferably designed as appropriate so that a desired oscillation frequency is obtained between about 0.1 to 1 μm.

  Similarly to the oscillation element 15B, the oscillation elements 15C and 15D exhibit high-frequency oscillation characteristics in an electric field larger than the threshold electric field Eth. In each semiconductor device 100 incorporating the oscillation elements 15C and 15D, an electric field is radiated into the space from the patch antenna. It was confirmed that

(Embodiment 2)
In the present embodiment, a semiconductor device having a structure different from that of the first embodiment will be described with reference to FIGS. FIG. 12 is a top view showing the semiconductor device of this embodiment. FIG. 13 is an enlarged view of the vicinity of the oscillation element in the cross section taken along line EE in FIG. For the sake of simplicity, the same components as those in the first embodiment are denoted by the same reference numerals.

  As shown in FIGS. 12 and 13, the semiconductor device 200 of this embodiment is formed on a substrate 1 having an n-type semiconductor layer 2 </ b> E having a convex portion 18 e at the top, and an upper surface of the substrate 1. A signal line 5 extending over the convex portion 18e of the semiconductor layer 2E, a ground line 6 formed on the lower surface of the substrate 1 and forming the signal line 5 and the transmission line, and a signal line on the upper surface of the substrate 1 5 is formed on the substrate 1, and is formed on the substrate 1. The oscillation element 15 E is formed from the ground electrode 36 that is spaced apart from the ground 5 and connected to the ground line 6, the n-type semiconductor layer 2 E, the signal line 5, and the ground electrode 36. And a high-frequency circuit 11 connected to the signal line 5.

  Specifically, in this embodiment, a mother substrate formed of non-doped semi-insulating GaAs is prepared, and an Si-doped GaAs thin film is formed on this mother substrate by epitaxial growth as an n-type semiconductor layer 2E. It is used as the substrate 1.

  The signal line 5 and the ground line 6 are directly formed on the substrate 1 using a metal thin film having a film thickness of about 5 μm to form a microstrip type transmission line, and the ground electrode 36 penetrates the substrate 1. It is grounded through a contact plug 37 filling the via hole.

  In this embodiment, the ohmic contact is formed by forming AuGeNi or an AuGe alloy at the contact interface between the signal line 5 and the ground electrode 36 with respect to the n-type semiconductor layer 2E and performing a heat treatment at 300 ° C. Furthermore, in this embodiment, the signal line 5 and the ground electrode 36 are subjected to Au electroplating.

  The signal line 5 is connected to the bias terminal 8 through the bias line 8a to which the stub 10 is connected. That is, a DC voltage is applied to the n-type semiconductor layer 2E through the bias terminal 8 by an external power supply, and the oscillation element 15E formed of the signal line 5, the ground electrode 36, and the n-type semiconductor layer 2E is a gun. It is a diode.

  Furthermore, a patch antenna formed of a metal thin film is connected to both ends of the signal line 5 as the high-frequency utilization circuit 11, and the high-frequency power generated by the oscillation element 15E is designed to be radiated into the space. The shape of the patch antenna can be changed as appropriate according to the operating frequency band.

  Here, the oscillation element 15E will be further described with reference to FIG.

In the present embodiment, as shown in FIG. 13, in the oscillation element 15E, the n-type semiconductor layer 2E has a concentration of Si as an n-type impurity of 5 × 10 ¹⁷ (cm ⁻³ ) and a film thickness of about 0.2 μm. The n-semiconductor layer 2 is formed above and below the n-semiconductor layer 2, and the concentration of n-type impurities is higher than that of the n-semiconductor layer 2 (the concentration of Si as an impurity is 1 × 10 ¹⁹ (cm ^−3). )) N + semiconductor layers 12a and 12b. As shown in FIG. 13, the n− semiconductor layer 2 and the n + semiconductor layer 12a formed thereon form a convex portion 18e.

  Furthermore, the signal line 5 and the ground line 6 are formed directly on the substrate 1, but the signal line 5 is located on the n + semiconductor layer 12a particularly in the region where the n-type semiconductor layer 2E is formed. The ground line 6 is formed so as to overlap the n + semiconductor layer 12b with the substrate 1 interposed therebetween.

  In the present embodiment, the via hole is also formed so as to penetrate the n + semiconductor layer 12b. However, the present invention is not limited to this configuration. For example, a via hole may be formed in a region on the substrate 1 where the n-type semiconductor layer 2E is not formed, and the ground electrode 36, the ground line 6 and the contact plug may be connected.

  That is, the oscillation element 15E of the present embodiment has substantially the same structure as the oscillation element 15 described in the first embodiment, and the ground electrode 36 is formed by the contact plug 37 that fills the ground line 6 with the via hole penetrating the substrate 1. The only difference is that they are connected.

  Also in the semiconductor device 200 of the present embodiment, as in the first embodiment, the signal line 5 and the ground line 6 that constitute the transmission line, the oscillation element 15E, and the high-frequency utilization circuit unit connected to the signal line 5 (this embodiment) In this embodiment, the patch antenna) 11 is incorporated into one substrate. That is, in the semiconductor device 200, the oscillation element 15E 'is mounted with the above accuracy without using flip chip mounting or the like. Therefore, in the semiconductor device 200 of this embodiment, variation in characteristics in the terahertz band is suppressed.

  Also in the semiconductor device 200 of the present embodiment, it is not necessary to connect the oscillation element 15E to the high frequency utilization circuit 11 using a wire or a bump. For this reason, the transmission line length is shortened compared to the pill type package and the flip chip mounting, and the signal transmission loss can be reduced from the millimeter wave band to the terahertz band. Accordingly, it is possible to efficiently transmit a high frequency signal to a space or an external circuit through the high frequency utilization circuit unit 11.

  In particular, the microstrip transmission line has been sufficiently analyzed for its high-frequency characteristics, and a highly accurate model is provided in electromagnetic field simulation. Therefore, the semiconductor device 200 of the present embodiment is very useful when it is necessary to design a microstrip type transmission line with high accuracy.

  Further, particularly in the present embodiment, a desired oscillation frequency can be obtained by appropriately designing the thickness L of the n − semiconductor layer 2. In a general semiconductor device manufacturing process, the thickness L of the n − semiconductor layer 2 can be easily reduced, for example, compared to the distance between wirings, and the film thickness can be controlled to about 1 nanometer. Can also be realized. Accordingly, it is easy to operate the oscillation element 15E at a higher frequency, and it is possible to provide a semiconductor device having a very high frequency and good controllability of the oscillation frequency.

  In the semiconductor device 200 of the present embodiment, one oscillation element 15E is provided, but the present invention is not limited to this. For example, in the semiconductor device 200 of the present embodiment, it is possible to form an oscillation element having a thickness L different from that of the n − semiconductor layer 2 at a different location on the substrate 1 from the oscillation element 15E. For this reason, if the semiconductor device 200 of this embodiment is used for a communication device used in a communication method using a plurality of different frequencies or a communication device that switches a plurality of frequency bands, the communication device can be reduced in size.

  Further, in this embodiment, if the substrate 1 is obtained by epitaxially growing the n-type semiconductor layer 2E on the InP substrate, the crystallinity of the n-type semiconductor layer 2E becomes almost equal to that of the single crystal material, and the characteristics of the oscillation element 15E are obtained. The effect of improving is also obtained.

(Other embodiments)
In each of the above embodiments, based on the impurity concentration of the n-type semiconductor layers 2A, 2B, 2C, 2D and 2E of the oscillation elements 15, 15B, 15C, 15D and 15E and FIG. Thickness (in the case of the oscillation elements 15B and 15C, the height of the convex portion, in the case of the oscillation element 15D, the lower surface of the n + semiconductor region 12d in the convex portion 18d and the lower surface of the n + semiconductor layer 12d in contact with the ground line 6 L) is in the range of 0.1 to 10 μm, but in applications not intended for high-frequency operation, the thickness L of the n − semiconductor layer 2 may be 10 μm or more.

  Further, it is empirically required that the impurity concentration in which the dipole mode and the hybrid mode are generated is a shaded area shown in FIG. Therefore, based on FIG. 17, the n-type semiconductor layers 2A, 2B, 2C, 2D and 2E of the oscillation elements 15, 15B, 15C, 15D and 15E mentioned above are selected according to the characteristics required for the oscillation element for each application. The impurity concentration may be selected as appropriate.

  Furthermore, in the semiconductor device of each embodiment, the n-type semiconductor layers 2A, 2B, 2C, 2D, and 2E of the oscillation elements 15, 15B, 15C, 15D, and 15E are direct transition type compound semiconductors having a zinc flash structure. Any material that exhibits a cancer effect may be used. Specifically, the direct transition type compound semiconductor having a zinc flash structure is GaAs, InP, InSb, ZnSe, CdTe, or a mixed crystal thereof. Note that n-type impurities introduced into the n-type semiconductor layers 2A, 2B, 2C, 2D, and 2E are Si, S, and Se when the n-type semiconductor layers 2A, 2B, 2C, 2D, and 2E are formed of InP. Or the like may be used if S is formed from GaAs.

Furthermore, in the semiconductor device of each embodiment, the n-type semiconductor layers 2A, 2B, 2C, 2D, and 2E of the oscillation elements 15, 15B, 15C, 15D, and 15E are formed by epitaxial growth using the gas source MBE method. Si-doped Ga _x an in may be formed by _{(1-x) N y As} (1-y). Here, 0 ≦ x ≦ 0.53 and 0.05 ≦ y ≦ 0.2, and the doping concentration of Si, which is an n-type impurity, is preferably 1 × 10 ¹⁷ (cm ⁻³ ). Thus, by introducing N into the GaInAs semiconductor, the saturation rate of electrons in GaInAs is reduced and the oscillation frequency of the oscillation element is slightly reduced, but the operation of the oscillation element is increased in stability. Therefore, for applications that require stable operation, the n-type semiconductor layers 2A, 2B, 2C, 2D, and 2E are formed by Si-doped Ga _x In _(1-x) N _y formed by epitaxial growth using the gas source MBE method. The semiconductor device 100 formed of As _(1-y) is very suitable.

  Furthermore, in each of the above-described embodiments, a mother substrate formed of Fe-doped semi-insulating InP or non-doped semi-insulating GaAs is prepared as the substrate 1, and the n-type semiconductor layer 2A, Although a substrate in which a Si-doped InP thin film or a Si-doped GaAs thin film is formed by epitaxial growth as 2B, 2C, 2D, or 2E is used as the substrate 1, it is not limited to this. For example, a substrate formed of ceramics, benzocyclobutene (BCB), polyimide resin, liquid crystal polymer, or the like may be used as the mother substrate. In particular, when a substrate formed of ceramics, benzocyclobutene (BCB), polyimide resin, liquid crystal polymer, or the like is used as a mother substrate, it is easier to obtain materials than when a semiconductor substrate is used as a mother substrate. Cost can be reduced.

  In the present embodiment, the case where the Gunn diode is used as the oscillation elements 15, 15B, 15C, 15D, and 15E has been described. However, the present invention is not limited to the Gunn diode, and other two-terminal elements that exhibit negative resistance characteristics are used. Is also possible. Examples of other two-terminal elements exhibiting negative resistance characteristics include IMPATT diodes using an avalanche phenomenon of electrons and tunnel diodes using negative resistance characteristics.

  In the present embodiment, the patch antenna is provided as the high-frequency utilization circuit 11 in the semiconductor device 100. However, the present invention is not limited to this, and other circuits that are utilized for high-frequency operation, such as filters, transmission lines, mixers, amplifiers, and the like. Of course, it is also possible to provide it.

  The present invention is useful for a high-frequency device or the like that needs to operate in a microwave band, a millimeter wave band, or a terahertz frequency band.

FIG. 1 is a top view showing a semiconductor device. FIG. 2 is an enlarged view of the vicinity of the oscillation element shown in FIG. 3A, 3B, and 3C are cross-sectional views taken along lines AA, BB, and CC in FIG. 2, respectively. 4 is a perspective view of the vicinity of the oscillation element shown in FIG. FIG. 5 is a cross-sectional view schematically showing the operation of the oscillation element. 6A to 6C are process cross-sectional views illustrating a method for manufacturing an oscillation element of a semiconductor device. 7A to 7C are process cross-sectional views illustrating a method for manufacturing an oscillation element of a semiconductor device. 8A to 8C are process cross-sectional views illustrating a method for manufacturing an oscillation element of a semiconductor device. FIG. 9 is a cross-sectional view of the oscillation element. FIG. 10 is a cross-sectional view of the oscillation element. FIG. 11 is a cross-sectional view of the oscillation element. FIG. 12 is a top view showing the semiconductor device. FIG. 13 is an enlarged view of the vicinity of the oscillation element in the cross section taken along line EE in FIG. FIG. 14 is a diagram schematically showing the principle of generating a gun effect in a planar type Gunn diode. FIG. 15 is a diagram showing the relationship between electric field strength and electron traveling speed in a Gunn diode using n-type GaAs. FIG. 16 is a diagram illustrating conditions under which the cancer effect occurs. FIG. 17 is a diagram illustrating f0 in the most basic dipole mode. FIG. 18 is a diagram illustrating an example in which a Gunn diode is flip-chip mounted on a flat circuit board constituting a microstrip line.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 n-semiconductor layer 2A, 2B, 2C, 2D 2E n-type semiconductor layer 4 Domain 5 Signal line 6 Ground line 7 Ground terminal 8 Bias terminal 8a Bias line 9 Air bridge 10 Stub 11 High frequency utilization circuit part (patch antenna)
12a, 12b, 12c n + semiconductor layer 12d n + semiconductor regions 15, 15B, 15C, 15D, 15E Oscillating elements 18, 18b, 18c, 18d, 18e
20 Resist 21 Opening 22 Opening 23 Resist 24a, 24b Opening 25 Metal Thin Film 36 Ground Electrode 37 Contact Plug 100, 200 Semiconductor Device

Claims (10)

A substrate having an n-type semiconductor layer having a convex portion at the top;
A signal line formed on the substrate and extending over the convex portion of the n-type semiconductor layer;
A grounding wire formed on the substrate, spaced apart from the signal line, and constituting the signal line and a transmission line;
An oscillation element including the n-type semiconductor layer, the signal line, and the ground line;
A high-frequency circuit unit formed on the substrate and connected to the signal line;
A semiconductor device comprising: The semiconductor device according to claim 1,
The n-type semiconductor layer is formed of a direct transition type compound semiconductor having a zinc flash structure,
The semiconductor device, wherein the oscillation element is a Gunn diode. The semiconductor device according to claim 2,
The semiconductor device, wherein the n-type semiconductor layer is formed of one type of compound semiconductor selected from the group consisting of GaAs, InP, InSb, ZnSe, and CdTe, or a mixed crystal of at least two types of compound semiconductors. The semiconductor device according to claim 2,
The n-type semiconductor layer is a semiconductor device formed of GaInNAs. The semiconductor device according to claim 1,
The high-frequency circuit unit is a semiconductor device including a patch antenna or a filter. A substrate having an n-type semiconductor layer having a convex portion at the top;
A signal line formed on the upper surface of the substrate and extending over the convex portion of the n-type semiconductor layer;
A ground line formed on the lower surface of the substrate and forming the signal line and the transmission line;
A ground electrode formed on the upper surface of the substrate and spaced apart from the signal line, and connected to the ground line;
An oscillation element including the n-type semiconductor layer, the signal line, and the ground electrode;
A high-frequency circuit unit formed on the substrate and connected to the signal line;
A semiconductor device comprising: The semiconductor device according to claim 6.
The n-type semiconductor layer is formed of a direct transition type compound semiconductor having a zinc flash structure,
The semiconductor device, wherein the oscillation element is a Gunn diode. The semiconductor device according to claim 7,
The semiconductor device, wherein the n-type semiconductor layer is formed of one type of compound semiconductor selected from the group consisting of GaAs, InP, InSb, ZnSe, and CdTe, or a mixed crystal of at least two types of compound semiconductors. The semiconductor device according to claim 7,
The n-type semiconductor layer is a semiconductor device formed of GaInNAs. The semiconductor device according to claim 6.
The high-frequency circuit unit is a semiconductor device including a patch antenna or a filter.

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