Semiconductor device

Abstract

[Problem] To provide a semiconductor device that makes it possible to improve output characteristics. [Solution] A semiconductor device according to an embodiment of the present disclosure comprises: a substrate; a conductive layer provided on the substrate; a first conductor facing the conductive layer; a first dielectric provided between the conductive layer and the first conductor; a diode electrically connected to the conductive layer and the first conductor and having a negative resistor; and at least one or more second dielectrics provided between the conductive layer and the first conductor.

Description

Semiconductor Devices

[0001] The present disclosure relates to semiconductor devices.

[0002] A patch antenna-type terahertz wave RTD oscillator has been proposed, in which a resonant tunneling diode (RTD) is integrated into a patch antenna. Compared to RTD oscillators integrated with other antennas, patch antenna-type oscillators have advantages such as unidirectional radiation and ease of circuit configuration and array fabrication. However, the standard design of patch antennas makes it impossible to increase the radiation conductance, which is an output index, above a certain value, resulting in the oscillator output being rate-limited at a certain value.

[0003] JP 2015-180047 A

[0004] The present disclosure provides a semiconductor device capable of improving output characteristics.

[0005] A semiconductor device according to one embodiment of the present disclosure includes a substrate, a conductive layer provided on the substrate, a first conductor facing the conductive layer, a first dielectric provided between the conductive layer and the first conductor, a diode having negative resistance electrically connected to the conductive layer and the first conductor, and at least one second dielectric provided between the conductive layer and the first conductor.

[0006] The semiconductor device may further include: a second conductor provided between the diode and the first conductor; and a third conductor provided between the second dielectric and the first conductor.

[0007] The thickness of the first dielectric may be λ / 200 or more, where λ is the effective wavelength in the first dielectric of electromagnetic waves at the operating frequency of the semiconductor device.

[0008] A distance between the diode and at least one of the second dielectric and the third conductor in a planar direction parallel to the substrate may be equal to or greater than λ / 200 where λ is the effective wavelength.

[0009] The conductive layer, the first conductor, and the first dielectric may have a resonant property, and the length of the first conductor in the planar direction may be at least λ / 10 or more where λ is the effective wavelength.

[0010] The conductive layer may include at least one of a dielectric, a semiconductor, or a metal.

[0011] The first dielectric may include two or more materials with different dielectric constants or conductivities.

[0012] The diode and a resonant structure formed of the second dielectric and the third conductor may be on the same plane parallel to the substrate.

[0013] The plurality of resonant structures may be arranged symmetrically about a center line on which the diode is located, or may be arranged rotationally symmetrically about a center point on which the diode is located.

[0014] The diode may be a resonant tunneling diode.

[0015] The semiconductor device may further include a power supply circuit electrically connected to at least one of the second conductor and the conductive layer, the power supply circuit including one or more filter circuits and a power supply terminal, and at least one shunt resistor element may be connected between the power supply circuit and the first conductor.

[0016] 1 is a perspective view showing a schematic configuration of a semiconductor device 1 according to a first embodiment. FIG. 2 is a cross-sectional view taken along the line A-A shown in FIG. 1. FIG. 3 is a perspective view showing an example of the structure of a diode. FIG. 4 is an equivalent circuit diagram of the semiconductor device as viewed from the diode. FIG. 5 is a characteristic diagram showing an example of antenna conductance and antenna conductance characteristics when the thickness of a first dielectric is changed. FIG. 6 is a characteristic diagram showing an example of radiation conductance characteristics when the thickness of a first dielectric is changed. FIG. 7 is a characteristic diagram showing an example of a comparison of output power between a conventional structure and a structure according to the present disclosure. FIG. 8 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a second embodiment. FIG. 9 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a third embodiment. FIG. 10 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a fourth embodiment. FIG. 11 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a fifth embodiment. FIG. 12 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a sixth embodiment. FIG. 13 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a seventh embodiment. FIG. 14 is a cross-sectional view showing the structure of a main part of a semiconductor device according to an eighth embodiment. FIG. 15 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a ninth embodiment. FIG. 16 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a tenth embodiment. FIG. 17 is a perspective view showing a schematic configuration of a semiconductor device according to an eleventh embodiment. FIG. 18 is a perspective view showing a schematic configuration of a semiconductor device according to a modification of the eleventh embodiment. FIG. 19 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a twelfth embodiment. FIG. 2 is a plan view showing the configuration of a power supply circuit.

[0017] Specific embodiments to which the present technology is applied will be described in detail below with reference to the drawings. The drawings are schematic or conceptual, and the proportions of each part are not necessarily the same as those in reality. In the specification and drawings, elements similar to those described above with reference to the previous drawings are given the same reference numerals, and detailed descriptions will be omitted as appropriate. Furthermore, the semiconductor device described in the following embodiments is applied to an oscillator that outputs terahertz electromagnetic waves, but can also be used as a detector that detects terahertz waves.

[0018] 1 is a perspective view showing a schematic configuration of a semiconductor device 1 according to a first embodiment, and FIG. 2 is a cross-sectional view taken along line AA shown in FIG.

[0019] The semiconductor device 1 shown in Figures 1 and 2 includes a substrate 110, a conductive layer 120, an antenna portion 130, a diode 140, a second conductor 150, and a resonant structure 160. In the following description, the arrangement and configuration of each portion of the semiconductor device 1 may be described using the x-axis, y-axis, and z-axis shown in each figure. The x-axis, y-axis, and z-axis are mutually orthogonal and represent the x-direction, y-direction, and z-direction, respectively. Furthermore, the z-direction may be described as upward and the opposite direction as downward. In this embodiment, the xy plane direction represents a plane direction parallel to the substrate 110. The z-direction represents a stacking direction perpendicular to the substrate 110.

[0020] The substrate 110 is a semiconductor substrate such as a GaN substrate, but may be a metal substrate, an insulating substrate, a polymer substrate, or a glass substrate instead of a semiconductor substrate.

[0021] The conductive layer 120 is provided on the substrate 110. The conductive layer 120 may be composed of a metal layer or a semiconductor layer, or may be a laminate of a metal layer and a semiconductor layer. The potential of the conductive layer 120 is set to a reference potential (GND).

[0022] 2, the antenna unit 130 has a first conductor 131 and a first dielectric 132. The first conductor 131 faces the conductive layer 120 in the z direction. The first dielectric 132 is provided between the conductive layer 120 and the first conductor 131. That is, the conductive layer 120 and the first conductor 131 face each other with the first dielectric 132 sandwiched between them. The material of the first dielectric 132 may be an oxide film, a nitride film, a resin, a resist, a plastic, a polymer, a ceramic, or a semiconductor material or an insulating material similar to these.

[0023] In this embodiment, the thickness t of the first dielectric 132 is preferably equal to or greater than λ / 200, where λ is the effective wavelength of the electromagnetic wave in the first dielectric 132 at the operating frequency of the semiconductor device 1 .

[0024] The diode 140 is electrically connected to the conductive layer 120 and the first conductor 131. The diode 140 has negative resistance. An example of a diode having negative resistance is a resonant tunneling diode. The diode 140 having negative resistance is configured using at least one material selected from the following: a binary mixed crystal, such as InN, InGaN, GaN, AlGaN, AlN, AlInN, AlInGaN, AlPN, InP, InGaAs, InAlAs, GaAs, AlGaAs, AlAs, AlGaAsSb, or AlSb, which combines one type each of a group III element (typically B, Al, Ga, or In) and a group V element (typically N, As, P, or Sb); a ternary or quaternary mixed crystal semiconductor, which combines three or more types; and SiGe. Here, an example of the structure of the diode 140 will be described with reference to FIG. 3 .

[0025] 3 is a perspective view showing an example of the structure of a diode 140. The diode 140 shown in FIG. 3 is a resonant tunneling diode. In the diode 140, an emitter layer 141, a first spacer layer 142, a first barrier layer 143, a quantum well layer 144, a second barrier layer 145, a second spacer layer 146, and a collector layer 147 are stacked in this order in the z direction on the conductive layer 120. In the diode 140, a lower electrode 148 is provided on the conductive layer 120, and an upper electrode 149 is provided on the collector layer 147.

[0026] The emitter layer 141 provided on the conductive layer 120 is made of, for example, n-type GaN. The first spacer layer 142 stacked on the emitter layer 141 is made of, for example, GaN. The first barrier layer 143 stacked on the first spacer layer 142 is made of, for example, AlN. The quantum well layer 144 stacked on the first barrier layer 143 is made of, for example, GaN. The second barrier layer 145 stacked on the quantum well layer 144 is made of, for example, AlN. The second spacer layer 146 stacked on the second barrier layer 145 is made of, for example, GaN. The collector layer 147 stacked on the second spacer layer 146 is made of, for example, n-type GaN.

[0027] In the diode 140 configured as described above, when a voltage is applied between the lower electrode 148 and the upper electrode 149, the current flowing decreases as the voltage increases in the negative resistance region.

[0028] 2 , the second conductor 150 is provided between the diode 140 and the first conductor 131 within the first dielectric 132. The diode 140 is electrically connected to the first conductor 131 by the second conductor 150. Note that the diode 140 may be in contact with the first dielectric 132 and electrically connected directly to it. In this case, the second conductor 150 is not necessary.

[0029] The resonant structure 160 includes a second dielectric 161 and a third conductor 162. The second dielectric 161 is provided on the conductive layer 120. The material of the second dielectric 161 can be an oxide film, a nitride film, a resin, a resist, a plastic, a polymer, a ceramic, or a similar semiconductor or insulating material. The material of the second dielectric 161 can be the same as or different from the material of the first dielectric 132.

[0030] The third conductor 162 is provided between the second dielectric 161 and the first conductor 131 within the first dielectric 132. The second dielectric 161 may be connected to the first dielectric 132 in contact therewith. In this case, the third conductor 162 is not necessary.

[0031] In this embodiment, it is desirable that the distance d between the diode 140 and the resonant structure 160 in the xy plane (a plane parallel to the substrate 110) is λ / 200 or more, where λ is the effective wavelength of the electromagnetic wave in the first dielectric 132.

[0032] A method for manufacturing the semiconductor device 1 according to this embodiment will be briefly described below.

[0033] First, the diode 140 is formed as a resonant tunneling diode on the substrate 110 using molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD). The diode 140 is made of at least one of the following materials: InN, InGaN, GaN, AlGaN, AlN, AlInN, AlInGaN, AlPN, InP, InGaAs, InAlAs, GaAs, AlGaAs, AlAs, AlGaAsSb, AlSb, the same as above, and SiGe. It is necessary to use a substrate 110 that is optimal for crystal growth, such as lattice matching conditions, in accordance with the material of the diode 140.

[0034] Next, the diode 140 is processed into a mesa shape using lithography and etching techniques. When the diode 140 is applied to an oscillator, it is necessary to cut out a submicron-sized mesa, so high-precision exposure techniques such as electron beam (EB) exposure may be used. In addition, it is necessary to use an optimal etchant, including selection of dry etching or wet etching, depending on the materials of the diode 140 and the substrate 110.

[0035] Next, the mesa of the diode 140 is covered with an oxide film, a nitride film, or the like for insulation protection, and the insulating film only above the diode 140 is removed using lithography and etching techniques to form an opening.

[0036] Next, the conductive layer 120 is formed by lithography and lift-off. The conductive layer 120 is made of at least one metal selected from the group consisting of Ti, Cr, Pt, Pd, Au, Ag, Cu, Ni, and Al.

[0037] Next, the second dielectric 161 is formed using lithography and etching techniques.

[0038] Next, lithography and etching techniques are used to form the first dielectric 132. The first dielectric is formed using at least one of an oxide film, a nitride film, a resin, a resist, a plastic, a polymer, a ceramic, or a similar semiconductor or insulating material.

[0039] Next, lithography and etching techniques are used to form a gap penetrating the first dielectric 132 .

[0040] Next, the second conductors 150 and the third conductors 162 are formed by filling the gaps with metal using lithography, lift-off, plating, or the like.

[0041] Finally, the first conductor 131 is formed by lithography and lift-off.

[0042] In the semiconductor device 1 manufactured by the above-described method, the substrate 110, the conductive layer 120 made of metal, the first dielectric 132 formed on the conductive layer 120, and the patch-shaped first conductor 131 formed on the first dielectric 132 constitute a patch antenna. The length of the patch antenna in the xy plane is at least λ / 10 or more, and preferably about λ / 4, where λ is the effective wavelength of the electromagnetic wave in the first dielectric 132 at the operating frequency of the semiconductor device 1.

[0043] The patch antenna may have any shape such as a square, a circle, or a polygon, and a slit, a slot, or an air gap may be introduced inside the patch antenna.

[0044] In the semiconductor device 1 according to this embodiment, the first conductor 131, the diode 140, and the conductive layer 120 are electrically connected through a via structure formed by the second conductor 150, thereby operating as an RTD oscillator. Here, the oscillation condition of the RTD oscillator is the Y parameter Y ＲＴＤ and the antenna Y parameter Y ａｎｔ can be defined by the following equations (1) and (2).

[0045] Since the diode 140 is biased in the negative conductance region, Re[Y ＲＴＤ ] is a negative value. The frequency that satisfies the above conditions is the oscillation frequency f ｏｓｃ is.

[0046] Conventional RTD oscillators do not include a resonant structure 160 configured by a second dielectric 161 and a third conductor 162. In contrast, the semiconductor device 1 according to this embodiment has the resonant structure 160 formed in the first dielectric 132. This solves the technical problems of the increased number of steps and difficulty in the manufacturing process. It also solves the technical problems of reduced design freedom and increased area per antenna element, which are caused by the distance between the resonator and the mesa being limited to a certain value or more. Furthermore, it solves technical problems such as lobe distortion due to interference with the resonator.

[0047] 4 shows an equivalent circuit of the semiconductor device 1 as viewed from the diode 140. In FIG. 4, the conductance G ｐ , inductance L ｐ , and capacitance C ｐ and the resistance R, inductance L, and capacitance C of the resonant structure 160. In this equivalent circuit, admittance Y seen from the diode 140 can be expressed by the following equation (3).

[0048] In the above formula (3), when we pay attention to the conductance (real part), the conductance G ｐ In addition to the resonant structure 160, a positive term R / X is added. Therefore, in this embodiment, the conductance can be increased compared to a conventional structure in which the resonant structure 160 does not exist.

[0049] The output power Pout of the RTD oscillator can be expressed by the following equation (4).

[0050] In equation (4), Y is the Y parameter of the RTD oscillator, and Y ａ is the Y parameter of the antenna part of the RTD oscillator, and G ｒａｄ is the radiation conductance, and V ａｃ is the AC voltage applied by the diode 140. Also, the radiation conductance G ｒａｄ is the antenna conductance G ａｎｔ and the product of radiation efficiency RE (G ｒａｄ= G ａｎｔ ×RE).

[0051] According to the above formula (4), the output power Pout of the semiconductor device 1 is proportional to the antenna conductance G ｒａｄ Therefore, the radiation conductance G ｒａｄ The larger the value of , the higher the output of the semiconductor device 1 becomes.

[0052] In a patch antenna with a conventional structure, the radiation conductance G ｒａｄ In contrast to this, in this embodiment, by forming the resonant structure 160 in the first dielectric 132, the antenna conductance G ａｎｔ Furthermore, as will be described later, the radiation efficiency RE is about the same as that of the conventional antenna, and as a result, the antenna conductance G ａｎｔ increases, and the output power P ｏｕｔ can be increased.

[0053] 5A is a characteristic diagram showing an example of the antenna conductance and the antenna conductance characteristics when the thickness of the first dielectric 132 is changed. In FIG. 5A, the horizontal axis represents the thickness t of the first dielectric 132. The first vertical axis represents the antenna conductance G ａｎｔ The second vertical axis represents the radiation efficiency RE. Figure 5A shows an antenna conductance characteristic curve C10 of the conventional structure, an antenna conductance characteristic curve C10 of the disclosed structure, a radiation efficiency characteristic curve C20 of the conventional structure, and a radiation efficiency characteristic curve C21 of the disclosed structure, when the operating frequency f is 500 GHz.

[0054] As explained in the equivalent circuit shown in FIG. 4, the antenna conductance G ａｎｔ is the antenna conductance G of the conventional structure, regardless of the thickness t of the first dielectric 132. ａｎｔ Furthermore, there is almost no difference in the radiation efficiency RE between the conventional structure and the structure disclosed herein. Therefore, according to this embodiment, compared to the conventional structure, the antenna conductance G ａｎｔcan be increased.

[0055] 5B is a characteristic diagram showing an example of the radiation conductance characteristic when the thickness of the first dielectric 132 is changed. In FIG. 5B, the horizontal axis represents the thickness t of the first dielectric 132. The vertical axis represents the radiation conductance G ｒａｄ 5B shows a radiation conductance characteristic curve C30 of the conventional structure and a radiation conductance characteristic curve C31 of the disclosed structure when the operating frequency f is 500 GHz. As shown in FIG. 5, the radiation conductance G ｒａｄ is about twice as large as that of the conventional structure. ｒａｄ can be increased.

[0056] 6 is a characteristic diagram showing an example of a comparison of output power between a conventional structure and the structure of the present disclosure. In FIG. 6, the horizontal axis represents the difference ΔI between the peak current and the valley current in the diode 140. The vertical axis represents the output power P ｏｕｔ 6 shows an output characteristic curve C40 of the conventional structure and an output characteristic curve C41 of the structure of the present disclosure. Note that the output characteristic curves C40 and C41 are obtained by dividing the capacitance C of the diode 140 by the output characteristic curve C41. ｄ 〜 is 10 fF, the difference ΔV between the peak voltage and the valley voltage in the diode 140 is 0.3 V, and the oscillation frequency f ｏｓｃ is derived by assuming that

[0057] According to FIG. 6, in the region where the difference ΔI is 0.008 A or more, the output power P ｏｕｔ is the output power P of the conventional structure ｏｕｔ In particular, when the difference ΔI is 0.014 A, the output power P is about 1.5 times that of the conventional structure. ｏｕｔ can be obtained.

[0058] When the value of ΔI is small, the output power of the new structure is lower than that of the conventional structure. This is because the antenna conductance G ａｎｔ is the antenna conductance G of the conventional structure ａｎｔTherefore, in order to obtain sufficient output power from the viewpoint of impedance matching, the negative conductance G of the diode 140 must be relatively high. ｄ , that is, a large difference ΔI needs to be applied.

[0059] 7 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a second embodiment. In FIG. 7, the same components as those in the semiconductor device 1 according to the first embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0060] In the semiconductor device 2 according to this embodiment, the shapes of the second conductor 150A and the third conductor 162A are different from those of the first embodiment. In each of the second conductor 150 and the third conductor 162 according to the first embodiment, the area of ​​the top surface that contacts the first conductor 131 is approximately the same as the area of ​​the bottom surface that contacts the diode 140 or the second dielectric 161. In other words, the shape of the second conductor 150A and the third conductor 162A in the XZ cross section is rectangular.

[0061] 7, the area of ​​the top surface of each of the second conductor 150A and the third conductor 162A is larger than the area of ​​the bottom surface. That is, the shape of the second conductor 150A and the third conductor 162A in the XZ cross section is a trapezoid with the area of ​​the upper base side larger than the area of ​​the lower base side.

[0062] In this embodiment, the gaps for forming the second conductors 150A and the third conductors 162A have a tapered shape in which the opening diameter narrows from the upper opening to the lower opening as the aspect ratio (depth / opening diameter) increases, resulting in the second conductors 150A and the third conductors 162A having trapezoidal cross-sectional shapes, as shown in FIG.

[0063] In the semiconductor device 2 according to the second embodiment configured as described above, similarly to the first embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162A is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0064] 8 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a third embodiment. In FIG. 8, the same components as those in the semiconductor device 1 according to the first embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0065] In the semiconductor device 2 according to this embodiment, the method for manufacturing the second conductor 150B and the third conductor 162B is different from that in the first embodiment. In the first embodiment, the voids for forming the second conductor 150B and the third conductor 162B are formed in the first dielectric 132 in a single etching step.

[0066] In contrast, in this embodiment, the first dielectric 132 and the voids are formed in stages over multiple steps. The second conductor 150B and the third conductor 162B are formed by filling the voids in each stage with metal. As a result, the second conductor 150B and the third conductor 162B have a so-called stacked via structure in which layers with large planar areas and layers with small planar areas are alternately stacked in the z direction.

[0067] In the semiconductor device 3 according to the third embodiment configured as described above, similarly to the first embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162B is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0068] 9 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a fourth embodiment. In FIG. 9, the same components as those in the semiconductor device 2 according to the second embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0069] The semiconductor device 4 according to this embodiment differs from the second embodiment in the relationship in size of the contact area between the second conductor 150C and the diode 140 and the relationship in size of the contact area between the third conductor 162C and the second dielectric 161. In the second embodiment, the areas of the contact surface between the second conductor 150A and the diode 140 are approximately the same. In addition, the areas of the contact surface between the third conductor 162A and the second dielectric 161 are also approximately the same.

[0070] 9 , the area of ​​the diode 140 is larger than the area of ​​the second conductor 150C at the contact surface between the second conductor 150C and the diode 140. Also, the area of ​​the second dielectric 161 is larger than the area of ​​the third conductor 162C at the contact surface between the third conductor 162C and the second dielectric 161.

[0071] In this embodiment, the gap tapers as the depth of the gap penetrating the first dielectric 132 increases. In this case, if the contact area between the diode 140 and the second conductor 150C is sufficiently large, the positioning of the second conductor 150C becomes easy. Also, if the contact area between the second dielectric 161 and the third conductor 162C is sufficiently large, the positioning of the third conductor 162C becomes easy.

[0072] In the semiconductor device 4 according to the fourth embodiment configured as described above, similarly to the second embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162C is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0073] 10 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a fifth embodiment. In FIG. 10, the same components as those in the semiconductor device 4 according to the fourth embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0074] In the semiconductor device 5 according to the present embodiment, the relationship in size of the contact area between the second conductor 150D and the diode 140 and the relationship in size of the contact area between the third conductor 162D and the second dielectric 161 are opposite to those in the fourth embodiment. That is, in the present embodiment, at the contact surface between the second conductor 150D and the diode 140, the area of ​​the diode 140 is smaller than the area of ​​the second conductor 150D, as shown in Fig. 10 . Also, at the contact surface between the third conductor 162D and the second dielectric 161, the area of ​​the second dielectric 161 is smaller than the area of ​​the third conductor 162D.

[0075] In this embodiment, if the contact area between the second conductor 150D and the diode 140 is sufficiently large, sufficient contact between the two can be ensured even if the diode 140 is miniaturized. Also, if the contact area between the third conductor 162D and the second dielectric 161 is sufficiently large, sufficient contact between the two can be ensured even if the second dielectric 161 is miniaturized.

[0076] In the semiconductor device 5 according to the fifth embodiment configured as described above, similarly to the fourth embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162D is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0077] 11 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a sixth embodiment. In FIG. 11, the same components as those in the semiconductor device 5 according to the fifth embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0078] In the semiconductor device 6 according to this embodiment, the relationship in size of the contact area between the third conductor 162E and the second dielectric 161 is opposite to that in the fifth embodiment. That is, in this embodiment, at the contact surface between the third conductor 162E and the second dielectric 161, the area of ​​the second dielectric 161 is larger than the area of ​​the third conductor 162E, as shown in Fig. 11 . Therefore, if the contact area between the second dielectric 161 and the third conductor 162E is sufficiently large, it becomes easy to position the third conductor 162E.

[0079] In the semiconductor device 6 according to the sixth embodiment configured as described above, similarly to the fifth embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162E is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0080] 12 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a seventh embodiment. In FIG. 12, the same components as those in the semiconductor device 6 according to the sixth embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0081] In the semiconductor device 7 according to this embodiment, the conductive layer 120 includes a semiconductor layer 121 stacked on the substrate 110 and a metal layer 122 stacked on the semiconductor layer 121. The semiconductor layer 121 is made of at least one of the following materials: InN, InGaN, GaN, AlGaN, AlN, AlInN, AlInGaN, AlPN, InP, InGaAs, InAlAs, GaAs, AlGaAs, AlAs, AlGaAsSb, AlSb, the same materials as above, and SiGe. The metal layer 122 is made of at least one of the following metals: Ti, Pt, Pd, Au, Ag, Cu, and Ni, as above.

[0082] Furthermore, in the semiconductor device 7 according to this embodiment, the diode 140 is disposed on the semiconductor layer 121. Therefore, the contact surface between the diode 140 and the second conductor 150G is located closer to the substrate 110 than the contact surface between the second dielectric 161 and the third conductor 162G. Furthermore, the surface of the diode 140 according to this embodiment is covered with the insulating film 170. Therefore, the diode 140 and the metal layer 122 are electrically insulated by the insulating film 170.

[0083] In the semiconductor device 7 according to the seventh embodiment configured as described above, similarly to the sixth embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162G is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0084] 13 is a cross-sectional view showing the structure of a main part of a semiconductor device according to an eighth embodiment. In FIG. 13, the same components as those in the semiconductor device 7 according to the seventh embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0085] In the semiconductor device 8 according to this embodiment, when forming a void penetrating the first dielectric 132, a portion of the upper surface of the second dielectric 161 is over-etched. As a result, a recess is formed in the upper surface of the second dielectric 161. A portion of the third conductor 162H is filled in this recess. Therefore, the contact area between the third conductor 162H and the second dielectric 161 is increased compared to the eighth embodiment and others. This improves the adhesion between the third conductor 162H and the second dielectric 161.

[0086] Furthermore, in the semiconductor device 8 according to the eighth embodiment configured as described above, similarly to the seventh embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162H is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0087] 14 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a ninth embodiment. In FIG. 14, the same components as those in the semiconductor device 7 according to the seventh embodiment are denoted by the same reference numerals, and redundant explanations will be omitted.

[0088] 14, in the semiconductor device 9 according to this embodiment, the second dielectric 161 also contacts the semiconductor layer 121, similar to the diode 140. In addition, the second dielectric 161 is surrounded by the metal layer 122.

[0089] In the semiconductor device 9 according to this embodiment configured as described above, similarly to the seventh embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162I is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power. In this embodiment, if the semiconductor layer 121 is made of a semiconductor material with high conductivity, it is possible to obtain output characteristics similar to those of the seventh and eighth embodiments.

[0090] Furthermore, in this embodiment, both the diode 140 and the second dielectric 161 are formed on the semiconductor layer 121. Therefore, it is possible to reduce the number of steps in the manufacturing process compared to the seventh and eighth embodiments described above.

[0091] 15 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a tenth embodiment. In Fig. 15, the same components as those in the semiconductor device 7 according to the seventh embodiment described above are denoted by the same reference numerals, and redundant explanations will be omitted.

[0092] In the semiconductor device 10 according to this embodiment, the second conductor 150J and the third conductor 162J are formed by vapor deposition on the inner surface of the gap penetrating the first dielectric 132. Therefore, the second conductor 150J and the third conductor 162J have a hollow shape. Note that, although both the second conductor 150J and the third conductor 162J are formed by vapor deposition in this embodiment, either one of them may be formed by vapor deposition. In other words, it is sufficient that at least one of the second conductor 150J and the third conductor 162J is formed by vapor deposition on the inner surface of the gap penetrating the first dielectric 132.

[0093] In the semiconductor device 10 according to this embodiment configured as described above, similarly to the seventh embodiment, the resonant structure 160 made up of the second dielectric 161 and the third conductor 162J is provided in the first dielectric 132. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power. In this embodiment, if the semiconductor layer 121 is made of a semiconductor material with high conductivity, it is possible to obtain output characteristics similar to those of the seventh and eighth embodiments.

[0094] 16 is a perspective view showing a schematic configuration of a semiconductor device according to an eleventh embodiment. In FIG. 16, the same components as those in the semiconductor device 1 according to the first embodiment described above are denoted by the same reference numerals, and redundant explanations will be omitted.

[0095] The semiconductor device 11 according to this embodiment is provided with two resonant structures 160. These two resonant structures 160 face each other in the x direction and are arranged symmetrically with respect to the center line of the conductive layer 120 extending in the y direction. A diode 140 is arranged on this center line. By arranging the two resonant structures 160 in this manner, it is possible to reduce the space required for the circuit configuration and improve the lobe. Note that the number of resonant structures 160 is not limited to two and may be more than one.

[0096] 17 is a perspective view showing a schematic configuration of a semiconductor device according to a modification of the eleventh embodiment. The semiconductor device 11B shown in FIG. 17 includes four resonant structures 160. Two pairs of resonant structures 160 facing each other in the x direction are arranged symmetrically with respect to a center line extending in the y direction. Furthermore, two pairs of resonant structures 160 facing each other in the y direction are arranged symmetrically with respect to a center line extending in the x direction. In other words, the four resonant structures 160 are arranged rotationally symmetrically with respect to the center point where the diode 140 is located. Arranging the four resonant structures 160 in this manner can reduce the space required for the circuit configuration and improve the lobe.

[0097] Each of the plurality of resonant structures 160 arranged as described above is composed of the second dielectric and the third conductor described in any one of the first to eleventh embodiments. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0098] 12th Embodiment Fig. 18 is a cross-sectional view showing the structure of a main part of a semiconductor device according to a twelfth embodiment. In Fig. 18, the same components as those in the semiconductor device 1 according to the first embodiment described above are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0099] The semiconductor device 12 according to this embodiment further includes a power supply circuit 180 in addition to the components of the semiconductor device 1 according to the first embodiment. The configuration of the power supply circuit 180 will now be described with reference to FIG.

[0100] 19 is a plan view showing the configuration of the power supply circuit 180. The power supply circuit 180 has a power supply terminal 181, a filter 182, and a shunt resistor element 183.

[0101] The feed terminal 181 is configured as a coplanar waveguide (CPW). For example, the feed terminal 181 has a shape in which the conductive layer 120 extends through an end face of the first dielectric 132 to the same plane as the first conductor 131. Note that the configuration of the feed terminal 181 is not limited to a coplanar waveguide. For example, the feed terminal 181 may be configured as a microstrip in which terminals are provided on the first conductor 131 and the conductive layer 120, respectively, or as a coplanar waveguide with grounds in which contact vias are introduced to periodically connect the first conductor 131 and the conductive layer 120.

[0102] The filter 182 blocks RF (Radio Frequency) signals while transmitting DC and IF (Intermediate Frequency) signals. The filter 182 may be a metal-insulator-metal (MIM) filter, an RLC filter, a filter using a coupler, a filter using an active element, or any other filter that has a filtering function in a desired band.

[0103] The shunt resistor 183 is a stabilizing resistor that suppresses parasitic oscillation of the diode 140. The shunt resistor 183 is made of a semiconductor or a conductor with low conductivity. The conductance value of the shunt resistor 183 is at least equal to the negative conductance G of the diode 140. ｄ and is set to a value that is larger than 1 / 2 and that can suppress parasitic oscillation of the diode 140 in the low frequency (IF) region. The shunt resistance element 183 is formed using lithography, a lift-off method, a plating method, or the like. Note that, in this embodiment, two shunt resistance elements 183 are provided in the power supply circuit 180, but the number of shunt resistance elements 183 is not particularly limited as long as it is at least one.

[0104] The semiconductor device 12 configured as described above is provided with the resonant structure 160 described in any one of the first to eleventh embodiments. Therefore, the antenna conductance G ａｎｔ Therefore, it is possible to increase the output power.

[0105] The present technology can be configured as follows:

[0106] (1) A semiconductor device comprising: a substrate; a conductive layer provided on the substrate; a first conductor facing the conductive layer; a first dielectric provided between the conductive layer and the first conductor; a diode having negative resistance electrically connected to the conductive layer and the first conductor; and at least one second dielectric provided between the conductive layer and the first conductor.

[0107] (2) The semiconductor device according to (1), further comprising: a second conductor provided between the diode and the first conductor; and a third conductor provided between the second dielectric and the first conductor.

[0108] (3) The semiconductor device according to (1) or (2), wherein the thickness of the first dielectric is λ / 200 or more, where λ is the effective wavelength in the first dielectric of electromagnetic waves at the operating frequency of the semiconductor device.

[0109] (4) The semiconductor device according to (3), wherein a distance between the diode and at least one of the second dielectric and the third conductor in a planar direction parallel to the substrate is λ / 200 or more where λ is the effective wavelength.

[0110] (5) The semiconductor device according to (3) or (4), wherein the conductive layer, the first conductor, and the first dielectric have resonant properties, and the length of the first conductor in the planar direction is at least λ / 10 or more where λ is the effective wavelength.

[0111] (6) The semiconductor device according to any one of (1) to (5), wherein the conductive layer includes at least one of a dielectric, a semiconductor, and a metal body.

[0112] (7) The semiconductor device according to any one of (1) to (6), wherein the first dielectric includes two or more materials having different dielectric constants or electrical conductivities.

[0113] (8) The semiconductor device according to (2), wherein the diode and a resonant structure made up of the second dielectric and the third conductor are present on the same plane parallel to the substrate.

[0114] (9) The semiconductor device according to (8), wherein the plurality of resonant structures are arranged in line symmetry with respect to a center line on which the diode is located, or in rotational symmetry with respect to a center point on which the diode is located.

[0115] (10) The semiconductor device according to any one of (1) to (9), wherein the diode is a resonant tunneling diode.

[0116] (11) The semiconductor device according to any one of (1) to (10), further comprising a power supply circuit electrically connected to at least one of the second conductor and the conductive layer, the power supply circuit including one or more filter circuits and a power supply terminal, and at least one or more shunt resistor elements connected between the power supply circuit and the first conductor.

[0117] It should be noted that the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, the effects described in this specification are merely examples and are not intended to be limiting, and other effects may also be obtained.

[0118] 1 to 12: Semiconductor device 110: Substrate 120: Conductive layer 131: First conductor 132: First dielectric 140: Diode 150: Second conductor 160: Resonant structure 161: Second dielectric 162: Third conductor 180: Power supply circuit 181: Power supply terminal 182: Filter 183: Shunt resistor element

Claims

1. A semiconductor device comprising: a substrate; a conductive layer provided on the substrate; a first conductor facing the conductive layer; a first dielectric provided between the conductive layer and the first conductor; a diode having negative resistance electrically connected to the conductive layer and the first conductor; and at least one second dielectric provided between the conductive layer and the first conductor.

2. The semiconductor device according to claim 1, further comprising: a second conductor provided between said diode and said first conductor; and a third conductor provided between said second dielectric and said first conductor.

3. The semiconductor device of claim 2, wherein the conductive layer, the first conductor, and the first dielectric have resonant properties, and the length of the first conductor in a planar direction parallel to the substrate is at least λ / 10, where λ is the effective wavelength in the first dielectric of electromagnetic waves at the operating frequency of the semiconductor device.

4. The semiconductor device according to claim 3, wherein said conductive layer comprises at least one of a dielectric, a semiconductor, or a metal body.

5. The semiconductor device according to claim 3, wherein said first dielectric includes two or more materials having different dielectric constants or electrical conductivities.

6. The semiconductor device according to claim 3, wherein said diode and a resonant structure consisting of said second dielectric and said third conductor are present on the same plane parallel to said substrate.

7. The semiconductor device according to claim 6, wherein a plurality of said resonant structures are arranged symmetrically about a center line on which said diode is located, or are arranged rotationally symmetrically about a center point on which said diode is located.

8. The semiconductor device according to claim 3, wherein the diode is a resonant tunneling diode.

9. The semiconductor device according to claim 3, further comprising a power supply circuit electrically connected to at least one of the second conductor and the conductive layer, the power supply circuit including one or more filters and a power supply terminal, and at least one shunt resistor element connected between the power supply circuit and the first conductor.

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