JP6668979B2 - Semiconductor device and electric circuit - Google Patents

Description

  The present invention relates to a semiconductor device in which a light emitting unit that emits light and a current control unit that controls the current of the light emitting unit are integrated. Further, the present invention relates to an electric circuit including the semiconductor element.

  In an LED package for lighting or the like, a plurality of series-connected circuits in which a plurality of LED chips are connected in series to obtain a large luminous flux are further connected and arranged in parallel. For this reason, when a short circuit occurs in a certain LED chip among the LEDs constituting the LED package, the current is concentrated in a series connection circuit including the LED chip due to a decrease in drive voltage. As a result, it develops and expands into various problems. For example, an overcurrent flows in a series connection circuit including a short-circuited LED chip, and the deterioration of the LED chip accelerates. Further, since almost no current flows in the other series-connected circuits, the light emission pattern of the LED package is significantly deteriorated.

  Patent Document 1 describes an LED light source device provided with a constant current circuit for each series connection circuit so that current does not concentrate on the series connection circuit including the short-circuited LED chip.

  Patent Document 2 discloses a semiconductor device made of a group III nitride semiconductor in which a light emitting portion and a constant current device having an HFET structure for controlling the current of the light emitting portion to be constant are integrally formed on the same substrate. Have been. With such an integrated structure, the overall size can be reduced, and the cost can be reduced.

Japanese Patent No. 4461576 JP 2009-71220 A

  However, in the semiconductor device of Patent Document 2, since the HFET structure includes an AlGaN layer, it is necessary to insert an AlGaN layer in the n-layer even in the structure of the light-emitting portion, which is conventionally used as a light-emitting device made of a group III nitride semiconductor. The existing structure could not be diverted. Therefore, there has been a problem that the manufacturing cost is high.

  Therefore, the present invention is to realize a semiconductor element in which a light emitting unit and a current control unit for controlling a current of the light emitting unit are integrally formed.

The present invention is a semiconductor device having a light-emitting portion and a current control portion for controlling a current of the light-emitting portion, wherein the light-emitting portion is made of an intrinsic or n-type channel layer and a material having the same composition as the channel layer. A n-type layer having a higher n-type impurity concentration than the channel layer, a light-emitting layer, a semiconductor layer formed of a semiconductor stacked in the order of the p-layer, and a p-electrode located on the p-layer. a first groove extending from a partial region of the p-layer to the n-layer, a second groove extending from the bottom of the first groove to the channel layer, and a position facing the p-electrode with the second groove interposed in plan view. A source electrode provided on the n-layer exposed on the bottom surface of the first groove, a gate insulating film provided in a film shape continuously on the bottom surface and side surfaces of the second groove, and a bottom surface of the second groove and a side surface, has a gate electrode formed via a gate insulating film, a channel layer and the n Is a semiconductor device which is a FET structure homozygous by.

  The channel layer desirably has an n-type impurity concentration sufficiently lower than that of the n-layer, and particularly desirably intrinsic, in order to sufficiently improve current controllability by the current controller.

  The current control unit may further include a gate electrode provided on the bottom surface and the side surface of the second groove via a gate insulating film. Further, the p electrode and the gate electrode may be electrically connected.

  Further, the current control unit may further include a drain electrode provided at a position facing the source electrode with the second groove interposed therebetween in a plan view and provided on the bottom surface of the first groove. Further, the light emitting section may have a plurality of n electrodes connected to the n layer, and the drain electrode may be electrically connected to the plurality of n electrodes.

  The present invention can be applied to any semiconductor material conventionally used as a light emitting element, but is particularly effective to be applied to a semiconductor element made of a group III nitride semiconductor.

  Further, a plurality of light emitting units and current control units may be provided. For example, a structure may be employed in which a plurality of series circuits in which one or more light emitting units and a current control unit are connected in series, and a plurality of series circuits are connected in parallel. In the semiconductor device having such a structure, an output terminal is provided with a potentiometer connected to the gate electrode of each current control unit of each series circuit to form an electric circuit, and the voltage applied to the gate electrode is varied by the potentiometer. It may be. The value of the saturation current value can be controlled.

  In addition, it has five or more light-emitting parts, and one or more light-emitting parts are connected in series with four terminal points A, B, C, and D between A and B so as to be in the forward direction from A to B. One or more light emitting units are connected in series between DC so as to be in a forward direction from D to C, and between CB so as to be in a forward direction from C to B. The above-mentioned light-emitting units are connected in series, one or more light-emitting units are connected in series between DA, so as to be in the forward direction from D to A, and between BD, in the forward direction from B to D. In such a case, one or more light emitting units and the current control unit may be connected in series. In such a semiconductor device, the output terminal may be provided with a potentiometer connected to the gate electrode of the current control unit to form an electric circuit, and the voltage applied to the gate electrode may be varied by the potentiometer. The value of the saturation current value can be controlled.

  According to the present invention, it is possible to realize a semiconductor device in which the light emitting unit and the current control unit for controlling the current of the light emitting unit are integrally formed, so that the size of the device can be reduced. In addition, a structure used in a conventional light emitting device made of a group III nitride semiconductor can be used for the light emitting portion, and cost reduction can be achieved.

FIG. 2 is a diagram illustrating a configuration of a semiconductor element according to the first embodiment. FIG. 2 is a circuit diagram equivalent to the semiconductor element of the first embodiment. 4 is a graph showing IV characteristics of the semiconductor device of Example 1. FIG. 9 is a diagram illustrating a configuration of a semiconductor device according to a second embodiment. FIG. 9 is a diagram illustrating a configuration of an electric circuit according to a third embodiment. FIG. 9 is a diagram illustrating a configuration of a semiconductor device according to a fourth embodiment. FIG. 14 is a diagram illustrating a configuration of a semiconductor device according to a fifth embodiment. FIG. 14 is a diagram illustrating a configuration of a semiconductor device according to a sixth embodiment. FIG. 13 is a diagram illustrating a configuration of a semiconductor element according to a seventh embodiment. FIG. 14 is a diagram showing an electrode pattern of the semiconductor element of the sixth embodiment. The figure which showed the structure of the electric circuit of a modification. FIG. 9 is a diagram illustrating a configuration of a semiconductor element according to a modification.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments.

  FIG. 1 is a diagram illustrating a configuration of a semiconductor device according to a first embodiment. The semiconductor device according to the first embodiment is a flip-chip type device made of a group III nitride semiconductor, and includes a light emitting unit 10 that emits light and a current control unit 11 that controls a current of the light emitting unit 10. I have. The light emitting unit 10 is a region that functions as a light emitting diode that emits light. The current control unit 11 is a region having a function of controlling the current flowing through the light emitting unit 10, and has a function equivalent to that of the FET. As shown in FIG. 2, the semiconductor device of the first embodiment is equivalent to a circuit in which a light emitting diode (light emitting unit 10) and an FET (current control unit 11) are connected in series, and the cathode of the light emitting diode is connected to the drain of the FET. It is a connected configuration.

(Configuration of the light emitting unit 10)
First, the configuration of the light emitting unit 10 will be described in detail. As shown in FIG. 1, the light emitting unit 10 is located on the substrate 100 via a buffer layer (not shown) made of AlN on the substrate 100, and includes a channel layer 101, an n layer 102, a light emitting layer 103, and a p layer 104. It is composed of a layer made of a group III nitride semiconductor stacked in order, a transparent electrode 105 located on the p-layer 104, and a p-electrode 107 located on the transparent electrode 105 via an insulating film 106.

  The substrate 100 is a sapphire substrate, and its surface is provided with a periodic concavo-convex pattern for improving light extraction efficiency.

  The channel layer 101 is located on the surface of the substrate 100 on the side where the concave / convex pattern is provided via a buffer layer (not shown) made of AlN. The channel layer 101 is undoped GaN having a thickness of 1 μm.

Note that the channel layer 101 may be intrinsic or n-type, as long as it functions as a channel layer of the current control unit 11. That is, the Si concentration of the n-layer 102 may be higher than that of the channel layer 101. In order to function sufficiently as a channel layer and improve the current controllability of the current controller 11, the channel layer 101 preferably has a sufficiently low Si concentration with respect to the n-layer 102. For example, the Si concentration is 1 ×. It may be a GaN layer of 10 ¹⁷ / cm ³ or less. In particular, it is desirable to make it undoped as in the first embodiment.

  The n-layer 102, the light-emitting layer 103, and the p-layer 104 are stacked on the channel layer 101 in this order. N layer 102 is made of n-GaN. The light emitting layer 103 has an MQW structure in which well layers made of InGaN and barrier layers made of AlGaN are alternately stacked. The p layer 104 is made of p-GaN.

  Note that the configurations of the channel layer 101, the n-layer 102, the light-emitting layer 103, and the p-layer 104 are not limited to those described above, and may be any configuration conventionally used in a light-emitting element made of a group III nitride semiconductor. For example, the n-layer 102 has an n-contact layer made of n-GaN, an electrostatic breakdown voltage layer in which undoped GaN and n-GaN are stacked in order, and an n-GaN and InGaN layer which are alternately and repeatedly stacked from the channel layer side. A structure in which n superlattice layers are sequentially stacked can be employed. The p-layer 104 has a structure in which a p-cladding layer in which p-AlGaN and p-InGaN are alternately and repeatedly laminated from the light-emitting layer 103 side, and a p-contact layer made of p-GaN are laminated in this order. Can be. In particular, the channel layer 101 can have the same composition as the contact layer of the n-layer 102.

  The transparent electrode 105 is made of IZO (zinc-doped indium oxide), and is provided on almost the entire surface of the p layer 104. In addition to IZO, ITO (tin-doped indium oxide), ICO (cerium-doped indium oxide), ZnO, or the like can be used.

The insulating film 106 is made of SiO ₂ , and is provided over substantially the entire surface of the transparent electrode 105. The insulating film 106 may have a DBR structure in which dielectrics having different refractive indices (for example, SiO ₂ and TiO ₂ ) are alternately stacked at a predetermined thickness. By efficiently reflecting the light, the light extraction efficiency can be improved.

  The p-electrode 107 is provided on the insulating film 106. The insulating film 106 is provided with a hole penetrating the insulating film 106, and the transparent electrode 105 and the p-electrode 107 are electrically connected through the hole. As the plane pattern of the p-electrode 107, the one used for the conventional light emitting element can be used as it is.

  The light emitting unit 10 described above has the same configuration as the conventional light emitting element, and also has the same function. That is, blue light is emitted by conduction.

(Configuration of Current Control Unit 11)
Next, the configuration of the current control unit 11 will be described in detail. As shown in FIG. 1, the current control unit 11 includes a channel layer 101, an n-layer 102, a source electrode 110, a gate insulating film 111, a gate electrode 112, a drain electrode 113, a first groove 114 exposing the n-layer 102, a channel, The second groove 115 exposes the layer 101.

  The first groove 114 is a groove formed by etching from the p layer 104 side, and has a depth reaching the n contact layer of the n layer 102. The region where the first groove 114 is formed is a region that functions as the current control unit 11. In manufacturing a conventional light-emitting element, a groove for exposing an n-layer is provided by dry etching to provide an n-electrode, but the first groove 114 can be used.

  The second groove 115 is a groove formed by further etching the n-layer 102 exposed by the first groove 114, and has a depth reaching the channel layer 101.

  The side surfaces of the first groove 114 and the second groove 115 may be perpendicular to the bottom surface or may be inclined.

  The source electrode 110 and the drain electrode 113 are separately provided on the n-layer 102 exposed on the bottom surface of the first groove 114. In addition, the source electrode 110 and the p-electrode 107 are provided to face each other with the second groove 115 therebetween in plan view, and the source electrode 110 and the drain electrode 113 are provided with the second groove 115 therebetween in plan view. They are provided facing each other.

The gate insulating film 111 is made of SiO ₂ , and is provided in a film shape continuously on the bottom and side surfaces of the second groove 115. In the first embodiment, the same material is used for the insulating film 106 and the gate insulating film 111, and the structure is simplified by integrating them. Gate insulating film 111 has a thickness of, for example, 0.1 μm. Note that different materials may be used for the insulating film 106 and the gate insulating film 111.

  The gate electrode 112 is made of Ti / Al, and is provided on the bottom surface and the side surface of the second groove 115 via the gate insulating film 111.

  The current control unit 11 described above is a region that functions as an FET. In other words, the vicinity of the surface of the channel layer 101 exposed on the bottom surface of the second groove 115 operates as a channel, and the amount of electrons flowing from the drain electrode 113 to the source electrode 110 is controlled by applying a voltage to the gate electrode 112. By doing so, the value of the saturation current between the source and the drain can be controlled.

  Although the drain electrode 113 does not contribute to the function of the constant current operation of the current control unit 11, the drain electrode 113 is provided when the structure of the conventional light emitting element is used for the semiconductor element of the first embodiment. This makes it easy to optimize the electrode pattern.

  Next, the operation of the semiconductor device of the first embodiment will be described. The semiconductor device of the first embodiment has a configuration in which a light emitting unit 10 functioning as a light emitting diode and a current control unit 11 functioning as an FET are connected in series (see FIG. 2). Therefore, when a voltage is applied between the p-electrode 107 of the light-emitting unit 10 and the source electrode 110 of the current control unit 11, the light-emitting unit 10 changes the gate voltage applied to the gate electrode 112 of the current control unit 11. , And emits light.

  FIG. 3 is a graph showing a result obtained by simulation of an IV characteristic of the semiconductor device of Example 1. For comparison, the IV characteristics of the light emitting unit 10 and the current control unit 11 are also shown in the graph. As shown in FIG. 3, the light emitting unit 10 has the same IV characteristics as a normal light emitting diode, and has a characteristic in which a current suddenly flows when a forward voltage is exceeded. Further, the current control unit 11 has a characteristic that the current increases as the voltage increases, but the current is saturated at a certain voltage or more and becomes a constant value, and has the same IV characteristics as the FET. You can see that it is. In the semiconductor device of the first embodiment, since the light emitting unit 10 and the current control unit 11 are connected in series, as shown in FIG. 3, when the forward voltage is exceeded, the current increases substantially linearly. Saturates to a constant value.

  As described above, according to the semiconductor device of the first embodiment, the light emitting unit 10 and the current control unit 11 for controlling the current of the light emitting unit 10 to be constant at a certain voltage or higher can be integrally realized as one device. Can be reduced in size and cost. Further, in the semiconductor device of the first embodiment, the structure of the conventional light emitting device can be used as the device structure of the light emitting unit 11, so that the cost can be reduced.

  In particular, the semiconductor device of Example 1 is effective when a light-emitting device having a structure in which a plurality of n-electrodes are dispersed is used. By providing the plurality of n-electrodes in the light emitting unit 10 and providing the drain electrode 113 of the current control unit 11 as one electrode electrically connected to the plurality of n-electrodes, the electrode pattern of the semiconductor element of the first embodiment is set. Can be easily performed. That is, the current diffusion in the element surface direction can be optimized, the light emission pattern can be easily made uniform, and the constant current operation in the current control unit 11 can be optimized.

  As an example, a flip-chip type semiconductor device shown in FIG. 12 is shown. In the semiconductor element of FIG. 12, a plurality of dot-shaped holes 120 are provided in the insulating film 106 covering the transparent electrode 105, and a reflective electrode 121 connected through the holes 120 is provided on the insulating film 106. I have. The light is reflected toward the sapphire substrate 100 by the reflective electrode 121 to improve the light extraction efficiency. Further, a plurality of dot-shaped holes 123 for exposing the n-layer 102 are provided, and the n-layer 102 exposed on the bottom surface of the hole 123 is provided with an n-electrode 122, respectively. Further, an insulating film 124 is provided so as to cover the reflective electrode 121, the n-electrode 122, and the insulating film 106. In the insulating film 124, a p wiring electrode 125 connected to the reflective electrode 121 is provided, and connected to the p electrode 107 provided on the insulating film 124. Further, in the insulating film 124, an n-wire electrode 126 connected to the plurality of n-electrodes 122 is provided, and is provided separately so as not to contact the p-wire electrode 125. The drain electrode 113 is provided continuously from over the insulating film 124 to the surface of the n-layer 102 exposed at the bottom of the groove 114. The drain electrode 113 on the insulating film 124 and the n-wiring electrode 126 are connected via a hole. I have. In the semiconductor device of FIG. 12, the pattern of the p-electrode 107 and the n-electrode 122 used in the conventional flip-chip type light-emitting device is realized as it is, and the setting of the electrode pattern is easy.

  FIG. 4 is a circuit diagram showing a configuration of a circuit equivalent to the semiconductor element of the second embodiment. As shown in FIG. 4, the semiconductor device of the second embodiment has a series circuit in which m light emitting units 10 and one current control unit 11 are connected in series, and n series circuits are connected in parallel. In this configuration, the positive electrode of the DC power supply 200 is connected to the p-electrode 107 of the light emitting unit 10, and the source electrode 110 of the current control unit 11 is connected to the negative electrode of the DC power supply 200. Although m and n are arbitrary natural numbers, the figure shows a case where m = n = 3 for simplicity. Further, the semiconductor element of the second embodiment was realized by using m × n light emitting units 10 and n n current control units 11 of the semiconductor element of the first embodiment, and connecting those electrodes as described above. The device has a monolithic structure.

  The separation groove for separating the plurality of light emitting units 10 and the current control unit 11 may be formed up to the depth reaching the channel layer 101 or may be formed up to the depth reaching the substrate 100.

  In the semiconductor device of the second embodiment, even if a short circuit occurs in a certain light emitting unit 10, the current of the series circuit including the light emitting unit 10 is kept constant by the current control unit 11. Therefore, it is possible to prevent a normal light emitting unit 10 in the column from being acceleratedly deteriorated due to an overcurrent flowing through the series circuit including the shorted light emitting unit 10. Also, only the short-circuited light emitting unit 10 does not emit light, and the other light emitting units 10 emit light normally, so that the light emitting pattern is substantially maintained.

  In the semiconductor device according to the second embodiment, the entirety of m × n light emitting units 10 and n current control units 11 are realized by one semiconductor device, and the size and cost of the device are reduced. Each of the series circuits (m light emitting units 10 and one current control unit 11) may be configured as one semiconductor element and connected in parallel. Further, only one light emitting unit 10 and one current control unit 11 may be used as one semiconductor element.

  FIG. 5 is a circuit diagram illustrating a configuration of an electric circuit according to the third embodiment. The electric circuit according to the third embodiment is obtained by providing a potentiometer R to the semiconductor element according to the second embodiment. Both ends of the potentiometer R are connected to the p-electrode 107 of the light emitting unit 10 and the source electrode 110 of the current control unit 11, and the output terminal is connected to the gate electrode 112 of the current control unit 11. The potentiometer R is a type of a variable resistor, and has a variable resistance value depending on the rotation angle and position of a knob.

  In the electric circuit according to the third embodiment, the voltage value applied to the gate electrode 112 of the current control unit 11 can be changed by operating the knob of the potentiometer R to change the resistance value. The current value can be controlled.

  FIG. 6 is a circuit diagram showing a configuration of the semiconductor device of the fourth embodiment. As shown in FIG. 6, the semiconductor device of the fourth embodiment is obtained by adding a series circuit connected in anti-parallel to each series circuit of the semiconductor device of the third embodiment.

  The semiconductor device of the fourth embodiment can be driven by an AC power supply 400. Here, since the current control unit 11 is provided in the semiconductor element of the fourth embodiment, the maximum current flowing through each series circuit is suppressed, and the time for obtaining a constant current value is prolonged. As a result, the time during which light is shined at a constant brightness becomes longer, and the flicker of light is reduced. Also in the fourth embodiment, a potentiometer may be provided so that the voltage value applied to the gate electrode 112 of the current control unit 11 can be changed.

  FIG. 7 shows an equivalent circuit diagram of the semiconductor device of the fifth embodiment. The semiconductor device of the fifth embodiment is realized by using a plurality of light emitting units 10 and one current control unit 11 of the semiconductor device of the first embodiment, and connecting the p electrode 107 and the source electrode 110 as follows. The device has a monolithic structure. As shown in FIG. 7, the semiconductor device of the fifth embodiment is a device having a configuration in which a plurality of light emitting units 10 are formed as bridge circuits described below.

  In the bridge circuit, as shown in FIG. 7, the light emitting unit 10 is connected as follows with four points A, B, C, and D as connection points. N (n is a natural number) light emitting units 10 are connected in series between A and B so that A is at a high potential and the forward direction is established. Between the BDs, m (m is a natural number) light emitting units 10 and one current control unit 11 are connected in series so that B is at a high potential and the forward direction is established. Between the DCs, n light emitting units 10 are connected in series such that D is at a high potential and the forward direction is established. Between the CBs, n light emitting units 10 are connected in series such that C has a high potential and the forward direction is established. Between the DAs, n light emitting units 10 are connected in series such that D is at a high potential and the forward direction is established. The figure shows a case where m = n = 3 for simplicity.

  The semiconductor element of the fifth embodiment is driven by an AC power supply 500. When the point A has a high potential and the point C has a low potential, the light emitting units 10 connected in series in the order of A, B, D, C and C emit light by being energized. When the potential of the point C becomes high and the potential of the point A becomes low, the light emitting units 10 connected in series in the order of CBDDA emit electricity to emit light. In this way, the majority of the light emitting units 10 can emit light regardless of whether any of the points A and C has a high potential.

  Here, since the current control unit 11 is provided between the BDs of the semiconductor element of the fifth embodiment, the maximum current is suppressed, and the time for obtaining a constant current value is prolonged. As a result, the time during which light is shined at a constant brightness becomes longer, and the flicker of light is reduced. Further, in the semiconductor device of the fifth embodiment, since a structure equivalent to the circuit diagram of FIG. 7 is realized by one semiconductor device, the size and cost of the device are reduced.

  Similarly to the third embodiment, an electric circuit in which the potentiometer R is provided in the semiconductor element of the fifth embodiment may be configured (see FIG. 11). Both ends of the potentiometer R are connected to points B and D, respectively, and the output terminal is connected to the gate electrode 112 of the current controller 11. In this electric circuit, the voltage value applied to the gate electrode 112 of the current control unit 11 can be changed by operating the knob of the potentiometer R to change the resistance value, and the saturation current value can be controlled. it can.

  FIG. 8 is a diagram showing the configuration of the semiconductor device of the sixth embodiment. The semiconductor device according to the sixth embodiment is different from the semiconductor device according to the first embodiment in that a current controller 61 is provided instead of the current controller 11. The current control unit 61 has a structure in which the drain electrode 113 in the current control unit 11 is omitted. Other configurations are the same as those of the semiconductor device of the first embodiment.

  In the first embodiment, the drain electrode 113 is left in the current control unit 11 to ensure consistency with the electrode pattern of the original element. However, the drain electrode 113 is a component that does not contribute to the current control function of the current control unit 11. Therefore, by omitting the drain electrode 113 as in the semiconductor device of the sixth embodiment, the configuration of the device can be further simplified, and the cost can be reduced. In particular, the semiconductor device of Example 6 is particularly effective when the structure of a light-emitting device provided with one n-electrode without dispersing n-electrodes at a plurality of locations is used.

  For example, the pattern of the n-electrode in the conventional light-emitting element is used as the pattern of the source electrode 110 of the semiconductor element of the sixth embodiment, and the second groove 115 and the gate electrode 112 are located between the source electrode 110 and the p-electrode 107. Such a pattern may be used.

  A specific example is shown in FIG. FIG. 10A shows an electrode pattern of a light emitting element to be diverted, and FIG. 10B shows an electrode pattern of a semiconductor element of Example 6 using the diverted light emitting element. As shown in FIG. 10A, the light emitting element to be diverted is a rectangular element in plan view, the pattern of the p-electrode 107 is a linear wiring pattern along the long side, and the pattern of the n-electrode 108 is the opposite side. A linear wiring pattern is formed along a certain long side. As shown in FIG. 10B, in the semiconductor device of Example 6, the pattern of the p-electrode 107 is kept as it is, and the pattern of the n-electrode 108 is diverted almost as it is as the source electrode 110. A linear gate electrode 112 is provided along the long side between the source electrodes 110 and between the source electrodes 110.

  FIG. 9 is a diagram showing a configuration of the semiconductor device of the seventh embodiment. The semiconductor device according to the seventh embodiment is different from the semiconductor device according to the first embodiment in that a light emitting unit 80 and a current control unit 81 are provided instead of the light emitting unit 10 and the current control unit 11. 113 is omitted, and a p-electrode 807 is provided instead of the p-electrode 107. The p-electrode 807 is obtained by extending the p-electrode 107 onto the gate insulating film 111 of the current control unit 11. Further, an insulating film 106 is provided between the p-electrode 807 and the n-layer 102 so that the p-electrode 807 does not contact the n-layer 102. Other configurations are the same as those of the semiconductor device of the sixth embodiment.

  The semiconductor device of the seventh embodiment is equivalent to a circuit in which the anode of the light emitting diode and the gate of the FET are connected in the circuit diagram shown in FIG. 2, and the light emitting unit 80 can be driven by the current control unit 81 at a constant current. it can.

(Modification)
Although the semiconductor element of the embodiment is a flip-chip type element, the present invention is not limited to this, and is also applicable to a face-up type element, a vertical element which conducts vertically to the main surface of the substrate, and the like. can do.

  The semiconductor elements shown in Examples 6 and 7 each have one light emitting part and one current control part. It is also possible to realize.

  The semiconductor element of the present invention can be used for an LED package for lighting and the like.

Reference Signs List 10: light emitting unit 11: current control unit 100: substrate 101: channel layer 102: n layer 103: light emitting layer 104: p layer 105: transparent electrode 106: insulating film 107: p electrode 110: source electrode 111: gate insulating film 112 ： Gate electrode 113 ： Drain electrode

Claims (10)

A light emitting unit, a semiconductor device having a current control unit for controlling the current of the light emitting unit,
The light emitting section is
An intrinsic or n-type channel layer, a semiconductor layer made of a material having the same composition as the channel layer and having a higher n-type impurity concentration than the channel layer; ,
A p-electrode located on the p-layer,
The current controller,
A first groove extending from a partial region of the p-layer to the n-layer;
A second groove reaching the channel layer from the bottom surface of the first groove;
A source electrode provided on the n-layer exposed to the bottom surface of the first groove at a position facing the p-electrode with the second groove interposed therebetween in plan view;
A gate insulating film continuously provided in a film shape on a bottom surface and a side surface of the second groove;
A gate electrode provided on the bottom surface and the side surface of the second groove via the gate insulating film;
Having a homojunction FET structure of the channel layer and the n-layer,
A semiconductor element characterized by the above-mentioned.   2. The semiconductor device according to claim 1, wherein the p electrode and the gate electrode are electrically connected.   The said current control part further has the drain electrode provided in the position which opposes the said source electrode across the said 2nd groove | channel in planar view, and was provided in the said 1st groove | channel bottom. The semiconductor device according to claim 1. The light emitting unit has a plurality of n electrodes connected to the n layer,
The drain electrode is electrically connected to the plurality of n-electrodes,
4. The semiconductor device according to claim 3, wherein:   The semiconductor device according to claim 1, wherein the channel layer is intrinsic.   The semiconductor device according to claim 1, wherein the semiconductor is a group III nitride semiconductor. A plurality of series circuits in which the one or more light emitting units and the current control unit are connected in series;
A plurality of the series circuits are connected in parallel,
The semiconductor device according to any one of claims 1 to 6, wherein: It has five or more light emitting parts,
For four terminal points A, B, C, D,
Between AB, one or more of the light emitting units are connected in series so as to be in the forward direction from A to B,
Between DC, one or more of the light emitting units are connected in series so as to be in a forward direction from D to C,
One or more light emitting units are connected in series between CB so as to be in a forward direction from C to B,
Between the DAs, one or more of the light emitting units are connected in series so as to be in the forward direction from D to A,
Between the BDs, one or more of the light emitting units and the current control unit are connected in series so as to be in the forward direction from B to D.
The semiconductor device according to any one of claims 1 to 6, wherein: A semiconductor device according to claim 7,
An output terminal having a potentiometer connected to the gate electrode of each current control unit of each series circuit;
By the potentiometer, the voltage applied to the gate electrode was variable,
An electric circuit, characterized by: A semiconductor device according to claim 8,
An output terminal having a potentiometer connected to the gate electrode of the current control unit;
By the potentiometer, the voltage applied to the gate electrode was variable,
An electric circuit, characterized by:

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