JP2017112356A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device high in breakdown voltage and high in reliability.SOLUTION: A resistive field plate 5 including a spiral resistive element 10 and a meander resistive element 20 is disposed in a withstand voltage structure portion 3. The spiral resistive element 10 is disposed in a spiral planar layout surrounding the periphery of a high-potential-side region 1 to span from a high-potential-side region 1 side to a low-potential-side region 2 side. A spiral wire of the spiral resistive element 10 includes a conductive film layer 11 and a thin-film resistive layer 12 connected to each other. The meander resistive element 20 has both ends positioned in the high-potential-side region 1 and the low-potential-side region 2, respectively, and is disposed in a meandering planar layout. The meander resistive element 20 is disposed at the same level as that of the thin-film resistive layer 12 of the spiral resistive element 10, and faces in the depth direction the conductive film layer 11 of the spiral resistive element 10, sandwiching an interlayer insulating film therebetween. The conductive film layer 11 of the spiral resistive element 10 and the meander resistive element 20 constitute a field plate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a semiconductor device.

  2. Description of the Related Art Conventionally, a withstand voltage structure such as a high withstand voltage diode or a high withstand voltage MOSFET (Metal Oxide Field Effect Transistor) is a field plate (FP: Field Plate) in order to stably ensure a high withstand voltage. It is often equipped with. As the structure of the field plate, a resistive field plate (RFP) and a multiple field plate (MFFP) are known.

  The resistive field plate is composed of a thin film resistive layer arranged in a spiral planar layout surrounding the periphery of the high potential side region from the high potential side (high side side) region to the low potential side (low side side) region. The surface potential is controlled by resistance division (see Patent Documents 1 to 5 below). The multi-field plate is composed of a coupling capacitance between floating metal layers arranged in a concentric plane layout surrounding the periphery of the high-potential side region and in multiple layers (multiple) via an interlayer insulating film. The surface potential is controlled. In particular, the resistive field plate has a stronger surface potential forcing than a capacitively coupled multiple field plate, and is useful for ensuring a high breakdown voltage.

  Even if the resistive field plate is composed of a single spiral thin film resistive layer, if the thin film resistive layer is arranged so as to be spread over the breakdown voltage structure, in principle, the electric field strength of the breakdown voltage structure is It is kept uniform by the resistive field plate. However, when the surface area of the pressure resistant structure is large, the resistance value of the entire resistive field plate may be too high. In general, there is an advantage that the higher the resistance value of the entire resistive field plate, the smaller the current consumption. However, if the resistance value of the entire resistive field plate is too high, almost no current flows through the resistive field plate. This causes a demerit that the forcing force of the surface potential is lost.

  If the surface field forcing by the resistive field plate cannot be obtained, for example, it will be adversely affected by mobile ions trapped in the interlayer insulating film, making it difficult to keep the electric field distribution in the breakdown voltage structure uniform. Become. When the thin film resistive layer constituting the resistive field plate is formed of polysilicon (poly-Si) or the like, the resistance of the resistive field plate can be reduced by increasing the impurity dose in the polysilicon. However, since the thin film resistor layer constituting the resistive field plate and the constituent portion made of polysilicon in other circuit regions may be formed at the same time, it is not practical to increase the impurity dose in the polysilicon. .

  A configuration of a conventional resistive field plate will be described. 17 to 19 are plan views showing a planar layout of a main part of a conventional resistive field plate. 17 to 19, the same components are denoted by the same reference numerals. FIG. 17 is FIG. 6 of Patent Document 1 below. The resistive field plate shown in FIG. 17 has two spiral field layouts surrounding the high potential side region 101 so as to extend from the high potential side region 101 to the low potential side region 102 and so as not to cross each other. It consists of thin film resistance layers 103a and 103b. Compared with the case where one thin-film resistance layer having the same total length is used, the total length of each thin-film resistance layer 103a, 103b is shortened, and the surface potential is controlled by the combined resistance.

  FIG. 18 is FIG. 1 of Patent Document 2 below. The resistive field plate shown in FIG. 18 includes a plurality of metal layers 113 arranged in a concentric planar layout surrounding the high potential side region 101, and a thin film resistor layer 114 that electrically connects the adjacent metal layers 113 to each other. , Composed of. Reference numeral 112 denotes a contact (connection part) between the metal layer 113 and the thin-film resistance layer 114. By arranging the metal layers 113 in multiple layers on the thin film resistor layer 114 with the interlayer insulating film 115 interposed therebetween, the convenience of layout is improved. In addition, by arranging the thin film resistor layer 114 in a planar layout on a straight line that is oblique to the circumferential direction of the metal layer 113, the length of the thin film resistor layer 114 is increased, and the sheet resistance of the thin film resistor layer 114 is reduced. (FIG. 18B).

  FIG. 19 is FIG. 11 of Patent Document 3 below. The resistive field plate shown in FIG. 19 includes two thin-film resistance layers 123a and 123b, both ends of which are positioned on the high potential side region 101 side and the low potential side region 102 side, respectively, and arranged in a meandering plane layout. The ends of the thin film resistance layers 123 a and 123 b on the high potential side region 101 side are electrically connected to another thin film resistance layer 124 disposed in the high potential side region 101. Reference numerals 126a and 126b denote metal wires that electrically connect the ends of the thin film resistor layers 123a and 123b on the high potential side region 101 side and the other thin film resistor layers 124, respectively. Reference numerals 127 a and 127 b are metal wires that electrically connect the end portions of the thin film resistance layers 123 a and 123 b on the low potential side region 102 side and the control / evaluation circuit 128, respectively.

  In the resistive field plate shown in FIG. 19, the function of the resistive field plate is realized by the thin film resistive layers 123a, 123b, and 124, compared with the case where the thin film resistive layer is arranged in one spiral planar layout. The resistance value is reduced. Further, the thin film resistance layers 123a and 123b are arranged so that the convex portions formed in accordance with the meander period are opposed to each other, and an electric field is generated in the vicinity of the convex portion on the side not facing (hereinafter referred to as the outer convex portion). Avoids intensity peaks or electric field increases. The convex portions outside the thin film resistor layers 123a and 123b are connected to each other by a polysilicon tape 125 surrounding the periphery of the high potential side region 101, and the surface potential is stabilized by the polysilicon tape 125.

  Patent Document 4 listed below discloses a resistive field plate having a configuration in which one thin film resistive layer is arranged in a planar layout meandering on a field insulating film covering a field limiting ring (FLR). . In the following Patent Document 4, the electric field applied to the field insulating film is reduced by making the electric field applied to the field limiting ring and the electric field applied to the resistive field plate substantially the same.

  Patent Document 5 listed below discloses a resistive field plate having a structure in which a withstand voltage structure portion is divided into a plurality of sections and different thin film resistance layers are arranged in a planar layout meandering in each section. In the following Patent Document 5, the pressure-resistant structure portion is arranged in a planar layout having a shape including opposing linear portions and arc-shaped portions that connect the ends at both ends of the linear portions. By disposing different thin film resistance layers in linear portions and arc-shaped portions having different lengths in the radial direction, the resistance value of the entire resistive field plate is lowered.

JP 2000-022175 JP 2003-008009 A Special table 2003-533886 gazette JP 2000-252426 A Japanese Patent No. 5748353

  However, the conventional resistive field plate has the following problems. FIG. 16 is an explanatory view showing a problem of a conventional resistive field plate. When the function of monitoring the voltage of a part of the resistive field plate (voltage dividing resistor) and detecting the voltage applied to the entire resistive field plate is mounted, the product of the resistance value of the resistive field plate and the parasitic capacitance value (RC Time constant) affects the voltage detection time. Therefore, when a part of the resistive field plate is used as a voltage detection resistor (hereinafter referred to as a voltage detection resistor), the resistive field plate preferably has a small resistance value and a small total surface area.

  In Patent Document 1, the resistance value and the parasitic capacitance value of one thin film resistance layer are adjusted by increasing the number of thin film resistance layers constituting the resistive field plate and used as a voltage detection resistor. it can. However, the resistance value of the other thin film resistance layers also decreases at the same rate as that of one thin film resistance layer serving as a voltage detection resistor, so that there is a problem that current consumption increases. In Patent Documents 2 and 3, since the entire resistive field plate is connected, it is difficult to reduce the total surface area of the resistive field plate. That is, in Patent Documents 1 to 3, the resistance value and the total surface area of the resistive field plate cannot be adjusted simultaneously.

  In Patent Document 5, a plurality of thin film resistive layers constituting a resistive field plate are independently arranged, so that the resistance value and parasitic capacitance value of only one thin film resistive layer used as a voltage detection resistor are adjusted. It is also easy to do. However, as shown in FIG. 16A, the thin film resistance layer 140 is arranged in a planar layout meandering in a meandering pattern such that the distance w101 between the thin film resistance layers 140 is equal. In this case, since the arc-shaped portion 141 serving as the turning point of the meandering pattern of the thin-film resistance layer 140 has substantially the same potential, a voltage drop (voltage burden) hardly occurs in the arc-shaped portion 141. For this reason, a voltage is borne by the portion 143 of the interlayer insulating film sandwiched between the arc-shaped portion 141 of the meandering pattern of the thin-film resistance layer 140 and between the arc-shaped portion 141 and the end portion 142 of the thin-film resistance layer 140. As a result, the electric field concentrates on this portion 143. Due to this electric field concentration, the withstand voltage is lowered as compared with the case where the thin film resistive layer is arranged in one spiral plane layout.

  This problem can be avoided if the thin-film resistance layer 150 is arranged in a planar layout meandering in a meandering pattern in which the distance w102 between the arc portions 151 as the turning points is wide as shown in FIG. The decrease in breakdown voltage is suppressed. However, the width w102 of the portion 153 of the interlayer insulating film sandwiched between the arc-shaped portions 151 that turns the meandering pattern of the thin-film resistance layer 150 and between the arc-shaped portion 151 and the end portion 152 of the thin-film resistance layer 150 is Become wider. As a result, the area not covered with the thin-film resistance layer 150 increases, and it is easy to be adversely affected by surface charges such as mobile ions, resulting in characteristic fluctuations, malfunctions, malfunctions, and increased leakage current (leakage current). A new problem arises that reliability decreases. That is, in Patent Document 5, it is difficult to ensure the breakdown voltage and the reliability at the same time.

  An object of the present invention is to provide a highly reliable semiconductor device capable of ensuring a predetermined breakdown voltage in order to solve the above-described problems caused by the prior art.

  In order to solve the above-described problems and achieve the object of the present invention, a semiconductor device according to the present invention has the following characteristics. A first resistance element is provided inside the insulating film on the semiconductor substrate. A second resistance element facing the first resistance element in the depth direction is provided inside the insulating film with the insulating film interposed therebetween. The first resistance element has a part that is partially different in layer and material and that is continuous to a part other than the part. The second resistance element is opposed to the first resistance element in the depth direction at the part.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, a conductive film layer is disposed in the part of the first resistance element, and a thin film resistance layer is disposed in a part other than the part. To do.

  In the semiconductor device according to the present invention, in the above-described invention, the semiconductor substrate is provided with a second semiconductor region fixed at a lower potential than the first semiconductor region. A breakdown voltage region is provided between the first semiconductor region and the second semiconductor region. The breakdown voltage region electrically isolates the first semiconductor region and the second semiconductor region. The first resistance element is arranged in a spiral planar layout surrounding the first semiconductor region in the breakdown voltage region.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, the second resistance element is arranged in a meandering plane layout.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, the second resistance element is arranged in a spiral planar layout having a different frequency from the first resistance element.

  In order to solve the above-described problems and achieve the object of the present invention, a semiconductor device according to the present invention has the following characteristics. A semiconductor substrate is provided with a second semiconductor region fixed at a lower potential than the first semiconductor region. A breakdown voltage region is provided between the first semiconductor region and the second semiconductor region. The breakdown voltage region electrically isolates the first semiconductor region and the second semiconductor region. A first resistance element is provided in the breakdown voltage region. The first resistance elements are arranged in a spiral planar layout surrounding the periphery of the first semiconductor region. A second resistance element is provided opposite to a part of the first resistance element in the depth direction with an insulating film interposed therebetween. The second resistance element is arranged in a meandering planar layout or a spiral planar layout having a different number of turns than the first resistance element.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, the first resistance element is a thin film resistance layer.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, the first resistance element has a conductive film layer disposed in a part thereof and a thin film resistance layer disposed in a part other than the part. To do.

  In the semiconductor device according to the present invention, in the above-described invention, the second resistance element is arranged in a meandering plane layout, and a turn point of the meander pattern of the second resistance element is adjacent to the first resistance element. It is characterized by being located in the center between the spiral lines.

  In the semiconductor device according to the present invention, in the above-described invention, the second resistance element is arranged in a meandering plane layout, and the folding point of the meandering pattern of the second resistance element is on the spiral of the first resistance element. It is located in.

  In the semiconductor device according to the present invention as set forth in the invention described above, the second resistance element is a thin film resistance layer.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, the second resistance element is arranged at the same level as a portion other than the part of the first resistance element.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, the second resistance element is arranged in a layer different from the first resistance element.

  In the semiconductor device according to the present invention, in the above-described invention, the second resistance element is arranged in a meandering plane layout, and the second resistance element is arranged between a thin film resistance layer and a conductive film with a meandering point of the meander pattern interposed therebetween. The layers are alternately arranged.

  The semiconductor device according to the present invention is characterized in that, in the above-described invention, both ends of the first resistance element and the second resistance element are located in the first semiconductor region and the second semiconductor region, respectively.

  According to the above-described invention, two resistive elements that can be independently set can be stacked one above the other without increasing the chip area. Both of these first and second resistance elements have a function as a field plate having one end connected to a high potential and the other end connected to a low potential. For this reason, only one of the first and second resistance elements can be used as a voltage detection resistor with a reduced total length or total area.

  According to the semiconductor device of the present invention, it is possible to secure a predetermined breakdown voltage and improve the reliability.

3 is a plan view showing a planar layout of the breakdown voltage structure of the semiconductor device according to the first embodiment; FIG. FIG. 2 is a cross-sectional view showing a cross-sectional structure taken along a cutting line A-A ′ in FIG. 1. FIG. 6 is a cross-sectional view of another example of the cross-sectional structure taken along section line A-A ′ of FIG. 1. FIG. 2 is a cross-sectional view showing a cross-sectional structure taken along a cutting line B-B ′ in FIG. 1. FIG. 6 is a plan view showing a planar layout of another example of the breakdown voltage structure of the semiconductor device according to the first embodiment; 6 is a plan view showing a planar layout of a breakdown voltage structure of a semiconductor device according to a second embodiment; FIG. FIG. 7 is a cross-sectional view showing a cross-sectional structure taken along a cutting line D-D ′ in FIG. 6. FIG. 7 is a cross-sectional view showing a cross-sectional structure taken along a cutting line E-E ′ in FIG. 6. 7 is a plan view showing a planar layout of a breakdown voltage structure of a semiconductor device according to a third embodiment; FIG. FIG. 9 is a plan view showing a planar layout of a breakdown voltage structure of a semiconductor device according to a fourth embodiment; It is sectional drawing which shows the cross-section in the cutting line G-G 'of FIG. FIG. 10 is a plan view showing a planar layout of a breakdown voltage structure of a semiconductor device according to a fifth embodiment; FIG. 13 is a cross-sectional view showing a cross-sectional structure taken along a cutting line X-X ′ in FIG. 12. FIG. 10 is a circuit diagram showing a circuit configuration of a semiconductor device according to a sixth embodiment; FIG. 10 is a circuit diagram showing a circuit configuration of a semiconductor device according to a seventh embodiment; It is explanatory drawing which shows the problem of the conventional resistive field plate. It is a top view which shows the plane layout of the principal part of the conventional resistive field plate. It is a top view which shows the plane layout of the principal part of the conventional resistive field plate. It is a top view which shows the plane layout of the principal part of the conventional resistive field plate. FIG. 10 is a plan view showing a planar layout of a breakdown voltage structure of a semiconductor device according to an eighth embodiment; FIG. 15 is a plan view showing a planar layout of another example of the breakdown voltage structure of the semiconductor device according to the eighth embodiment; FIG. 22 is a cross-sectional view showing a cross-sectional structure taken along a cutting line H-H ′ in FIG. 21. FIG. 10 is a cross-sectional view showing an example of the structure of a semiconductor device according to a ninth embodiment. FIG. 10 is a cross-sectional view showing an example of the structure of a semiconductor device according to a ninth embodiment. FIG. 10 is a cross-sectional view showing an example of the structure of a semiconductor device according to a ninth embodiment.

  Hereinafter, preferred embodiments of a semiconductor device according to the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the accompanying drawings, it means that electrons or holes are majority carriers in layers and regions with n or p, respectively. Further, + and − attached to n and p mean that the impurity concentration is higher and lower than that of the layer or region where it is not attached. Note that, in the following description of the embodiments and the accompanying drawings, the same reference numerals are given to the same components, and duplicate descriptions are omitted.

(Embodiment 1)
The structure of the semiconductor device according to the first embodiment will be described. FIG. 1 is a plan view showing a planar layout of the breakdown voltage structure of the semiconductor device according to the first embodiment. 1A shows a planar layout of the entire resistive field plate (RFP) 5, and FIG. 1B shows an enlarged portion surrounded by a dotted rectangular frame of the resistive field plate 5 (FIG. 6). The same applies to 9, 10). Here, a case where a part of the resistive field plate 5 is used as a voltage detection resistor will be described as an example. The semiconductor device according to the first embodiment shown in FIG. 1 includes a high potential side region 1 in a breakdown voltage structure 3 between a high potential side (high side) region 1 and a low potential side (low side) region 2. A resistive field plate 5 is provided so as to surround it.

  The high potential side region 1 is arranged in a substantially rectangular planar layout, for example. In the high potential side region 1, a high side circuit section (not shown) and the like are arranged. The high-side circuit unit is, for example, a high-potential-side IGBT of two IGBTs (Insulated Gate Bipolar Transistors) connected in series constituting one phase of a half-bridge circuit serving as an output stage. This is a CMOS (Complementary MOS) circuit that operates with the emitter potential VS of the upper arm (hereinafter referred to as IGBT of the upper arm) as a reference potential and drives the IGBT of the upper arm. High potential side region 1 is electrically connected to power supply potential VB which is the highest potential of the high side circuit portion.

  In the low potential side region 2, for example, a low side circuit unit (not shown) is arranged. The low-side circuit unit is, for example, a CMOS circuit that operates with the ground potential GND as a reference potential and drives the n-channel MOSFET of the level-up level shift circuit. The low potential side region 2 is fixed to the lowest potential, for example, the ground potential GND. The withstand voltage structure 3 is arranged between the high potential side region 1 and the low potential side region 2 in, for example, a planar layout of a substantially rectangular frame shape. The breakdown voltage structure 3 is configured by a parasitic diode 4 described later, and electrically separates the high potential side region 1 and the low potential side region 2. A resistive field plate 5 is arranged in the pressure resistant structure 3 so as to be spread over the pressure resistant structure 3.

  The resistive field plate 5 is composed of two resistive elements 10 and 20. One resistance element (hereinafter referred to as a spiral resistance element) 10 surrounds the high potential side region 1 from the high potential side region 1 side (inner peripheral side) to the low potential side region 2 side (outer peripheral side). Arranged in an encircling spiral planar layout. The spiral resistance element 10 has a function of fixing the surface potential of the withstand voltage structure portion 3 and keeping the electric field strength of the withstand voltage structure portion 3 uniform. For example, the spiral lines of the spiral resistance element 10 are arranged at substantially equal intervals with substantially the same width. The reason is that the potential difference between the spiral lines of the spiral resistance element 10 becomes equal, so that the electric field strength of the withstand voltage structure 3 can be kept uniform, and the other resistance element 20 can be easily designed. Because it can. The spiral resistance element 10 has a configuration in which a part of the withstand voltage structure portion 3 (hereinafter referred to as a first withstand voltage structure portion) 3a is different in layer and material from another portion (hereinafter referred to as a second withstand voltage structure portion) 3b. It has become.

  Specifically, in the spiral resistance element 10, a conductive film layer 11 made of a conductive material such as metal is disposed in the first breakdown voltage structure 3a, and polysilicon in which impurities are dosed in the second breakdown voltage structure 3b, for example. A thin film resistive layer 12 made of a resistive material such as (poly-Si) is disposed. The conductive film layer 11 and the thin film resistance layer 12 constituting the spiral resistance element 10 are connected through a contact portion that penetrates an interlayer insulating film (not shown). In FIG. 1, the conductive film layer 11 is shown by a line thinner than the thin film resistance layer 12. The thin-film resistance layer 12 has a substantially rectangular frame shape in which the first breakdown voltage structure portion 3a is opened, and is arranged concentrically around the high potential side region 1. The conductive film layer 11 is electrically connected to each of the thin film resistance layers 12 at a level different from that of the thin film resistance layer 12 and forms a part of the spiral line of the spiral resistance element 10. That is, the conductive film layer 11 is arranged in a striped planar layout along the circumferential direction of the thin-film resistance layer 12.

  Here, for example, the number of spiral lines of the spiral resistance element 10 (the number of turns of the spiral line) is five, and each thin film resistance layer 12 forming each spiral line is first to fifth thin films in order from the inner peripheral side to the outer peripheral side. The resistance layers are 12a to 12e. The four linear conductive film layers 11 arranged in a striped planar layout are referred to as first to fourth conductive film layers 11a to 11d in order from the inner peripheral side to the outer peripheral side. The contact portions between each one end of the conductive film layer 11 and the thin-film resistance layer 12 are first to fourth in order from the inner peripheral side to the outer peripheral side, and denoted by reference numerals 13a to 13d. The contact portions between the other end of the conductive film layer 11 and the thin film resistance layer 12 are designated as fifth to eighth in order from the inner circumference side to the outer circumference side, and are denoted by reference numerals 14a to 14d. The other end of the conductive film layer 11 may be connected to an end portion of the thin film resistance layer 12 (12b to 12e) adjacent to the outer peripheral side. The open end (inner peripheral side end) of the innermost first thin film resistive layer 12a and the open end (outer peripheral end) of the outermost fifth thin film resistive layer 12e are the inner peripheral side of the spiral resistance element 10, respectively. It is the edge part 10a and the outer peripheral side edge part 10b.

  Of the spiral resistance element 10, the conductive conductive film layer 11 disposed in the first voltage withstanding structure portion 3 a has almost no voltage drop. For this reason, even if the resistive element 20 is disposed in the first breakdown voltage structure 3a so as to overlap the conductive film layer 11 as will be described later, it is possible to avoid adversely affecting the potential difference of the resistive element 20. In addition, the resistance value of the spiral resistance element 10 is increased to such an extent that the forcing force (field plate effect) of the surface potential of the breakdown voltage structure 3 can be obtained by the resistive thin film resistance layer 12 disposed in the second breakdown voltage structure 3b. be able to. The resistance value of the spiral resistance element 10 is not less than the resistance value of the resistance element 20 and is variously changed within a range in which the field plate effect can be secured.

  The ratio of the second breakdown voltage structure portion 3b in which the thin film resistance layer 12 of the spiral resistance element 10 is arranged is also variously changed within a range in which the field plate effect can be secured. Further, both ends of the spiral resistance element 50 and the resistance element 20 are electrically connected to the high potential side region 1 and the low potential side region 2, respectively. Since the potential difference between the high potential side region 1 and the low potential side region 2 is as high as 600 V or more, for example, when the thin film resistance layer 12 and the resistance element 20 of the spiral resistance element 10 are conductive films, the resistance value is low. Therefore, the high potential side region 1 and the low potential side region 2 may be short-circuited. For this reason, it is preferable that the thin film resistance layer 12 and the resistance element 20 of the spiral resistance element 10 are formed of a resistive material.

  Another resistance element (hereinafter referred to as a meandering resistance element) 20 is arranged in a different layer from the conductive film layer 11 of the spiral resistance element 10 in the first breakdown voltage structure portion 3a, and sandwiches an interlayer insulating film (not shown). The conductive film layer 11 faces the depth direction. The meandering resistance element 20 may be arranged at the same level as the thin film resistance layer 12 of the spiral resistance element 10. The meandering resistance element 20 is arranged in a planar layout in which both ends are electrically connected to the high potential side region 1 and the low potential side region 2 respectively and meander in a lightning bolt shape, for example. To meander in the form of lightning, meanders to form an acute angle at the turning point, and a line segment connecting the turning points (the apex of the acute angle) (hereinafter, referred to as a straight portion, which is sequentially labeled from the inner circumference side to the outer circumference side by reference numerals 21a to 21a. 21e) is formed in a zigzag pattern arranged obliquely with respect to the conductive film layer 11. The number of turns of the meandering pattern of the meandering resistance element 20 may be the same as the number of the conductive film layers 11.

  The resistance value of the meandering resistance element 20 is determined by, for example, a response time when a predetermined voltage value is detected. The resistance value of the meandering resistance element 20 can be adjusted, for example, by the width w of the meandering resistance element 20 (the length in the direction parallel to the conductive film layer 11 between the turns). The resistance value of the meandering resistance element 20 may be about several MΩ (for example, about 7 MΩ). Further, the meandering resistance element 20 is preferably arranged in a planar layout such that the potential difference ΔV between the portions of the spiral resistance element 10 intersecting the conductive film layer 11 (here, the respective folding points 22 of the meandering pattern) becomes equal. . Thereby, it is possible to avoid the concentration of the electric field locally on the meandering resistance element 20. Thus, the planar layout of the meandering resistance element 20 that avoids local electric field concentration can be easily designed, for example, by making the number of turns of the meandering pattern of the meandering resistance element 20 the same as the number of the conductive film layers 11. is there. For example, the number of turns of the meandering pattern of the meandering resistance element 20 is four, which is the same as the number of the conductive film layers 11, and the folding points of the meandering pattern (first to fourth turning points 22 a to 22 d in order from the inside to the outside). ) Are respectively located on the first to fourth conductive film layers 11a to 11d, the potential distribution of the meandering resistance element 20 is as follows.

  The potential of the inner end 20a to which the highest potential of the meandering resistance element 20 is applied is the same potential V [V: Volt] as the potential of the inner peripheral end 10a of the spiral resistance element 10. The potential of the outer end 20b to which the lowest potential of the meandering resistance element 20 is applied is 0 [V], which is the same as the potential of the outer peripheral end 10b of the spiral resistance element 10. In the spiral resistance element 10, the potentials of the innermost first conductive film layer 11 a and the first thin film resistance layer 12 a are 4/5 of the potential V [V] of the inner peripheral side end 10 a of the spiral resistance element 10. (= 4/5 × V [V]). The potentials of the second conductive film layer 11b and the second thin film resistance layer 12b are 3/5 of the potential V [V] of the inner peripheral side end 10a of the spiral resistance element 10 (= 3/5 × V [V]). ). The potentials of the third conductive film layer 11c and the third thin film resistance layer 12c are 2/5 of the potential V [V] of the inner peripheral side end 10a of the spiral resistance element 10 (= 2/5 × V [V]). ). The potentials of the fourth conductive film layer 11d and the fourth thin film resistance layer 12d are 1/5 of the potential V [V] of the inner peripheral side end 10a of the spiral resistance element 10 (= 1/5 × V [V]). ). That is, the potential difference between the spiral lines of the spiral resistance element 10 is 1/5 × V [V].

  On the other hand, the potential of the innermost first turning point 22a of the meandering resistance element 20 is 4/5 of the potential V [V] of the inner end portion 20a of the meandering resistance element 20 (= 4/5 × V [V]). ), Which is equal to the potential of the first conductive film layer 11a of the spiral resistance element 10. The potential of the second folding point 22b of the meandering resistance element 20 is 3/5 of the potential V [V] of the inner end 20a of the meandering resistance element 20 (= 3/5 × V [V]), and the spiral resistance element It is equal to the potential of ten second conductive film layers 11b. The potential of the third folding point 22c of the meandering resistance element 20 is 2/5 of the potential V [V] of the inner end 20a of the meandering resistance element 20 (= 2/5 × V [V]), and the spiral resistance element It is equal to the potential of the tenth third conductive film layer 11c. The potential of the outermost fourth folding point 22d of the meandering resistance element 20 is 1/5 of the potential V [V] of the inner end 20a of the meandering resistance element 20 (= 1/5 × V [V]). It is equal to the potential of the fourth conductive film layer 11 d of the spiral resistance element 10. That is, the potential difference ΔV between the conductive film layers 11 of the spiral resistance element 10 is 1/5 × V [V]. Thus, the consistency of the potential distribution can be easily obtained between the spiral resistance element 10 and the meandering resistance element 20.

  Next, a cross-sectional structure of the semiconductor device according to the first embodiment will be described. FIG. 2 is a cross-sectional view showing a cross-sectional structure taken along the section line A-A ′ of FIG. 1. FIG. 3 is a cross-sectional view of another example of the cross-sectional structure taken along section line A-A ′ of FIG. 1. FIG. 4 is a cross-sectional view showing a cross-sectional structure taken along the cutting line B-B ′ of FIG. 1. As shown in FIGS. 2 and 4, an n-type diffusion region 32, an n-type diffusion region 33 and a p-type diffusion region 34 are selectively provided on the front surface layer of the p-type semiconductor substrate 30. Yes. The p-type region 31 on the back side of the substrate is fixed at the lowest potential, for example, the ground potential GND. The p-type region 31 on the back side of the substrate means that these regions are not formed in a portion deeper from the front surface of the p-type semiconductor substrate 30 than the n-type diffusion regions 32 and 33 and the p-type diffusion region 34. This is a portion remaining as a p-type region.

  The n-type diffusion region 32 constitutes the high potential side region 1. In the n-type diffusion region 32, for example, a lateral p-channel MOSFET of a high side circuit portion (a CMOS circuit in which a lateral n-channel MOSFET and a lateral p-channel MOSFET are complementarily connected) is disposed. Further, in the p-type region 36 provided inside the n-type diffusion region 32, for example, a lateral n-channel MOSFET of the high side circuit portion is disposed. The n-type diffusion region 33 is disposed outside the n-type diffusion region 32 and is in contact with the n-type diffusion region 32. The depth of the n-type diffusion region 33 is shallower than the depth of the n-type diffusion region 32, for example. The p-type diffusion region 34 is disposed outside the n-type diffusion region 33 and is in contact with the n-type diffusion region 33. Inside the p-type diffusion region 34, for example, a p-type region 38 is provided so as to extend to the n-type diffusion region 33.

A parasitic diode 4 is formed at a pn junction between the p-type diffusion region 34 and the n-type diffusion region 33, and the high-potential side region 1 and the low-potential side region 2 are electrically separated by the parasitic diode 4. The n-type diffusion region 33 constitutes the breakdown voltage structure 3 in which the resistive field plate 5 (see FIG. 1) is disposed. The n-type diffusion region 33 is a region where most of the depletion layer expands when a reverse bias is applied to the parasitic diode 4, and this region is a breakdown voltage region. The p-type diffusion region 34 is a region constituting the low potential side region 2. That is, the n ⁺ type region 35 provided inside the n type diffusion region 32 functions as the cathode region of the parasitic diode 4, and the p ⁺ type region 39 provided inside the p type region 38 is the anode of the parasitic diode 4. Act as a region. The low-potential side region 2 is constituted by an n-type diffusion region (not shown) arranged by the p-type diffusion region 34. The p-type diffusion region 34 may be a part of the p-type semiconductor substrate 30 that remains in a slit shape so as to be exposed from the p-type region 31 on the back side of the substrate to the front surface of the substrate. The exposure on the front surface of the substrate means that the substrate is disposed in contact with a first insulating film 43 described later.

The first electrode 40 is electrically connected to the n-type diffusion region 32 through the n ⁺ -type region 35. The first electrode 40 is fixed to the power supply potential VB of the high side circuit section. The second electrode 41 is electrically connected to the p-type region 36 via a p ⁺ -type region 37 provided inside the p-type region 36. The second electrode 41 is fixed to the reference potential of the high side circuit section (the emitter potential VS of the IGBT of the upper arm). The third electrode 42 is fixed at the lowest potential, for example, the ground potential GND.

  On the front surface of the p-type semiconductor substrate 30, the first insulating film 43, the second insulating film 44, and the interlayer insulating film 45 are sequentially stacked except for the contact between the first to third electrodes 40 to 42 and the semiconductor portion. It is covered with an insulating layer. The first insulating film 43 is, for example, LOCOS (Local Oxidation of Silicon). The first to third electrodes 40 to 42 each extend on the interlayer insulating film 45. The first to third electrodes 40 to 42, the interlayer insulating film 45, and the conductive film layer 11 of the spiral resistance element 10 described later are covered with, for example, an interlayer insulating film 46.

Further, as shown in FIG. 3, a linear portion of the meandering pattern of the meandering resistance element 20 is provided inside the interlayer insulating film 45 covering the n-type diffusion region 33 between the n ⁺ -type region 35 and the p ⁺ -type region 39. 21a to 21e (hereinafter referred to as thin film resistance linear portions) are provided. The conductive film layer 11 (11a to 11d) of the spiral resistance element 10 is provided inside the interlayer insulating film 46 in the portion where the meandering resistance element 20 is provided (first breakdown voltage structure portion 3a). That is, in the first breakdown voltage structure portion 3a (cross section taken along the cutting line AA ′), a field plate having the meandering resistance element 20 as the first layer and the conductive film layer 11 of the spiral resistance element 10 as the second layer is configured. Has been.

  When the meandering resistance element 20 detects the reference potential of the high-side circuit section (the emitter potential VS of the IGBT of the upper arm), the innermost conductive film layer 11a of the spiral resistance element 10 and the meandering resistance element 20 The innermost thin-film resistance straight line portion 21 a is electrically connected to the second electrode 41. In addition, the outermost conductive film layer 11 d of the spiral resistance element 10 and the outermost thin film resistance linear portion 21 e of the meandering resistance element 20 are electrically connected to the third electrode 42.

  As shown in FIG. 4, one end of the conductive film layer 11 (11 a to 11 d) of the spiral resistance element 10 extends in the depth direction via the first to fourth contact portions 13 a to 13 d penetrating the interlayer insulating film 45. It is connected to the opposing thin film resistance layer 12 (12a-12d). The fifth thin-film resistance layer 12e on the outermost peripheral side of the spiral resistance element 10 is connected to the third electrode 42 facing in the depth direction via a fifth contact portion 13e penetrating the interlayer insulating film 45. That is, at the boundary between the first withstand voltage structure portion 3 a and the second withstand voltage structure portion 3 b (cross section along the cutting line BB ′), the thin film resistance layer 12 of the spiral resistance element 10 is the first layer, and the spiral resistance element 10 A field plate having a second conductive film layer 11 is formed.

  Although not shown in the drawing, the cross-sectional structure taken along the section line CC ′ passing through the fifth to eighth contact portions 14a to 14d between the other end of each conductive film layer 11 and each thin film resistance layer 12 of the spiral resistance element 10 is also spiral. A field plate having a thin film resistance layer 12 of the resistance element 10 as a first layer and a conductive film layer 11 of the spiral resistance element 10 as a second layer is configured.

  As shown in FIG. 3, when the power supply potential VB of the high side circuit section is detected by the meandering resistance element 20, the innermost conductive film layer 11 a of the spiral resistance element 10, and the meandering resistance element 20 The innermost thin film resistance straight line portion 21 a may be electrically connected to the first electrode 40 instead of the second electrode 42.

  Although not shown, the meandering resistance element 20 that serves as a voltage detection resistor for detecting the emitter potential VS of the IGBT of the upper arm and the meandering that serves as a voltage detection resistor for detecting the power supply potential VB of the high side circuit section. Both the resistor element 20 and the resistor element 20 may be disposed.

  Another example of the planar layout of the meandering resistance element 20 will be described. FIG. 5 is a plan view showing a planar layout of another example of the breakdown voltage structure of the semiconductor device according to the first embodiment. The semiconductor device according to the first embodiment shown in FIG. 5 is different from the semiconductor device according to the first embodiment shown in FIG. 1 in that the thin film resistance straight line portion 21 of the meandering resistance element 20 and the conductive film layer 11 of the spiral resistance element 10. This is the point where and intersect. In FIG. 5, the thin film resistance straight line portions of the meandering resistance element 20 are respectively given reference numerals 21 a to 21 f in order from the inner side to the outer side, and the folding points of the meandering pattern are given reference signs 22 a to 22 in order from the inner side to the outer side. 22e is attached.

  In this case, the electric potentials of the respective thin-film resistance linear portions 21b to 21e of the meandering pattern of the meandering resistance element 20 intersect at the intersections 23a to 23d with the conductive film layer 11 (11a to 11d) of the spiral resistance element 10, respectively. It becomes equal to the potential of the conductive film layer 11. Each potential difference ΔV between each folding point 22a to 22e of the meandering pattern of the meandering resistance element 20 and the contact portions 13a to 13d and 14a to 14d closest to the respective folding points 22a to 22e is possible as described above. It is preferable that they are all equal. For this reason, it is preferable that each thin film resistance linear part 21b-21e of the meandering pattern of the meandering resistance element 20 and each electrically conductive film layer 11 (11a-11d) of the spiral resistance element 10 cross | intersect at each middle point.

  Although not shown, the number of turns of the meandering resistance element 20 may be different from the number of the conductive film layers 11 of the spiral resistance element 10. In this case, if the number of turns j of the meandering resistance element 20 is n times the number i of the conductive film layers 11 of the spiral resistance element 10 (n: positive integer) (j = i × n), the spiral resistance element 10 and The potential distribution can be matched with the meandering resistance element 20.

  As described above, according to the first embodiment, the first resistance element in which a part of the thin film resistance layer is replaced with the conductive film layer having a different hierarchy and material is arranged, so that the first resistance element is interposed between the first resistance element and the first resistance element. The thin film resistance layer disposed so as to face the conductive film layer of the resistance element in the depth direction can be used as the second resistance element. As a result, two resistive elements whose conditions can be independently set can be stacked one above the other without increasing the chip area. Along with these first and second resistance elements, it functions as a field plate having one end connected to a high potential and the other end connected to a low potential. For this reason, only one of the first and second resistance elements can be used as a voltage detection resistor with a reduced total length or total area.

  For example, the first resistance element is a spiral resistance element, and the second resistance element is a meandering resistance element. In this case, the field plate effect by the spiral resistance element can be made less susceptible to surface charges, and a predetermined breakdown voltage can be ensured. In addition, a meandering resistance element having a smaller overall length or total area than the spiral resistance element can be used as a voltage detection resistor, for example. Since the product (RC time constant) of the resistance value and the parasitic capacitance value of the meandering resistance element is very small, for example, the response of voltage detection can be improved by using this meandering resistance element as a voltage detection resistor. . Thereby, it is possible to prevent an increase in current consumption. Therefore, the reliability can be improved as compared with the conventional case where the field plate is constituted by a plurality of meandering resistance elements.

(Embodiment 2)
Next, the structure of the semiconductor device according to the second embodiment will be described. FIG. 6 is a plan view showing a planar layout of the breakdown voltage structure of the semiconductor device according to the second embodiment. The semiconductor device according to the second embodiment is different from the semiconductor device according to the first embodiment in the meandering pattern of the meandering resistance element 50. Specifically, the meandering resistance element 50 includes a linear portion (hereinafter referred to as a thin film resistance linear portion) 51 made of a resistive material such as polysilicon and a linear portion (hereinafter referred to as a conductive film) made of a conductive material such as metal. And a meandering pattern that are alternately arranged with the turning point interposed therebetween.

  The thin-film resistance straight line portions 51 of the meandering pattern of the meandering resistance element 50 (reference numerals 51a to 51f in order from the inner side to the outer side) are arranged at the same level as the thin-film resistance layer 12 of the spiral resistance element 10, for example. The conductive film linear portions 52 of the meandering pattern of the meandering resistance element 50 (reference numerals 52a to 52e are sequentially attached from the inner side to the outer side), for example, are arranged at the same level as the conductive film layer 11 of the spiral resistance element 10. That is, the thin film resistance straight line portions 51a to 51f and the conductive film straight line portions 52a to 52e of the meandering pattern of the meandering resistance element 50 are arranged in different layers.

  Each thin film resistance linear portion 51 of the meandering pattern of the meandering resistance element 50 is arranged in a plane layout oblique to the conductive film layer 11 so as to intersect with each conductive film layer 11 of the spiral resistance element 10. The conductive film linear portions 52 of the meandering pattern of the meandering resistance element 50 are arranged between the conductive film layers 11 of the spiral resistance element 10 in a planar layout parallel to the conductive film layer 11. Further, the conductive film linear portions 52 of the meandering pattern of the meandering resistance element 50 are alternately arranged at equal intervals with the conductive film layers 11 of the spiral resistance element 10 in the direction from the inner peripheral side to the outer peripheral side, for example.

  Between the folding points of the meandering pattern of the meandering resistance element 50 (reference numerals 53a to 53j in order from the inside to the outside) and the contact portions 13a to 13d, 14a to 14d closest to the respective folding points 53a to 53j. Each potential difference ΔV is preferably as equal as possible as described above. For this reason, it is preferable that each thin-film resistance straight line portion 51 of the meandering pattern of the meandering resistance element 50 and each conductive film layer 11 of the spiral resistance element 10 intersect each other at their midpoints. The meandering point 53 of the meandering pattern of the meandering resistance element 50 is preferably located at the center between adjacent spiral lines of the spiral resistance element (between adjacent conductive film layers 11).

  In addition, a voltage drop that occurs when the inner end 50 a is set to a high potential with respect to the outer end 50 b of the meandering resistance element 50 does not substantially occur in the conductive film straight line 52 but only in the thin film resistance straight line 51. That is, the potential at the folding points 53 a to 53 j of the meandering pattern of the meandering resistance element 50 substantially depends on the voltage drop of the thin film resistance straight line portion 51. As a result, the potential differences ΔV between the folding points 53a to 53j of the meandering pattern of the meandering resistance element 50 and the contact portions 13a to 13d and 14a to 14d closest to the folding points 53a to 53j are made substantially equal. be able to.

  For example, the number of turns of the meandering pattern of the meandering resistance element 50 is 10. The straight portion of the meandering pattern of the meandering resistance element 50 has the thin film resistance straight portions 51a arranged on the innermost side, and the conductive film straight portions 52 (52a to 52e) and the thin film resistance straight portions 51 (51b to 51e) are alternately arranged. The thin film resistance straight line portion 51f is disposed on the outermost side. And when each thin film resistance linear part 51 of the meandering pattern of the meandering resistance element 50 and each electrically conductive layer 11 (11a-11d) of the spiral resistance element 10 are made to cross | intersect at each middle point, meandering resistance element 50 The potential distribution of is as follows.

  The potential of the inner end portion 50 a to which the highest potential of the meandering resistance element 50 is applied is the same potential V [V] as the potential of the inner peripheral side end portion 10 a of the spiral resistance element 10. The potential of the outer end portion 50b to which the lowest potential of the meandering resistance element 50 is applied is set to 0 [V], which is the same as the potential of the outer peripheral side end portion 10b of the spiral resistance element 10. As in the first embodiment, the potential of each spiral wire of the spiral resistance element 10 increases from the potential V [V] of the inner peripheral side end portion 10a to the potential of the outer peripheral side end portion 10b as the spiral wire is arranged on the outer peripheral side. The potential decreases by 1/5 × V [V] until reaching 0 [V].

  On the other hand, among the folding points (hereinafter referred to as first to tenth folding points) 53a to 53j of the meandering resistance element 50, the folding points located at both ends of the same conductive film linear portion 52 (52a to 52e). Have the same potential because almost no voltage drop occurs in each conductive film linear portion 52. In addition, since each conductive film layer 11 of the spiral resistance element 10 and each conductive film linear portion 52 of the meandering resistance element 50 are alternately arranged at equal intervals, each folding point of the meandering pattern of the meandering resistance element 50 The potential at the outermost turning point decreases from the potential V [V] of the inner end 50a to the potential 0 [V] of the outer end 50b by the same potential.

  That is, the potential of the first and second folding points 53a and 53b of the meandering pattern of the meandering resistance element 50 is 9/10 of the potential V [V] of the inner end portion 50a of the meandering resistance element 50 (= 9/10 × V [V]). The potential of the third and fourth turning points 53c and 53d of the meandering pattern of the meandering resistance element 50 is 7/10 of the potential V [V] of the inner end portion 50a of the meandering resistance element 50 (= 7/10 × V [ V]). The potential of the fifth and sixth turn-back points 53e and 53f of the meandering pattern of the meandering resistance element 50 is 5/10 of the potential V [V] of the inner end portion 50a of the meandering resistance element 50 (= 5/10 × V [ V]).

  The potentials of the seventh and eighth folding points 53g and 53h of the meandering pattern of the meandering resistance element 50 are 3/10 of the potential V [V] of the inner end portion 50a of the meandering resistance element 50 (= 3/10 × V [ V]). The potentials of the ninth and tenth turning points 53i and 53j of the meandering pattern of the meandering resistance element 50 are 1/10 of the potential V [V] of the inner end portion 50a of the meandering resistance element 50 (= 1/10 × V [ V]). The potential difference ΔV between these adjacent conductive film layers (each conductive film layer 11 and each conductive film linear portion 52) is 1/10 × V [V]. Thus, the consistency of the potential distribution can be easily obtained between the spiral resistance element 10 and the meandering resistance element 50.

  FIG. 7 is a cross-sectional view showing a cross-sectional structure taken along section line D-D ′ of FIG. 6. FIG. 8 is a cross-sectional view showing a cross-sectional structure taken along section line E-E ′ of FIG. 6. The cross-sectional structure taken along the cutting line A-A ′ in FIG. 6 is the same as that in the first embodiment (FIGS. 2 and 3). The cross-sectional structure taken along the cutting line B-B 'in FIG. 6 is the same as that in the first embodiment (FIG. 4). 7 and 8 show a configuration in which the meandering resistance element 20 detects the reference potential (the emitter potential VS of the IGBT of the upper arm) of the high side circuit section.

As shown in FIG. 7, the thin-film resistance linear portion 51 (51b) of the meandering resistance element 50 is placed inside the interlayer insulating film 45 covering the n-type diffusion region 33 between the p ⁺ -type region 37 and the p ⁺ -type region 39. ˜51f). The conductive film layer 11 (11a to 11d) of the spiral resistance element 10 and the conductive film linear part of the meandering resistance element 50 are formed on the interlayer insulating film 45 in the portion where the meandering resistance element 50 is provided (first breakdown voltage structure portion 3a). 52 (52a to 52e) are provided.

  The innermost conductive film linear portion 52 a of the meandering resistance element 50 is electrically connected to the second electrode 41. Although not shown, the outermost thin-film resistance linear portion 51 f of the meandering resistance element 50 is connected to the third electrode 42. Further, each conductive film straight line portion 52 of the meandering resistance element 50 is electrically connected to the thin film resistance straight line portion 51 opposed in the depth direction via the interlayer insulating film 45. The cross-sectional structure of the conductive film layer 11 of the spiral resistance element 10 is the same as that of the first embodiment.

  As shown in FIG. 8, each of the conductive film linear portions 52 penetrates through the interlayer insulating film 45 at the turning points 53 b, 53 d, 53 f, 53 h, and 53 j that are one ends of the conductive film linear portions 52 of the meandering resistance element 50. The thin film resistor linear portion 51 is opposed to the thin film resistor 51 in the depth direction through the contact portion. Although not shown in the drawing, the cross-sectional structure at the cutting line FF ′ passing through the folding points 53 a, 53 c, 53 e, 53 g, 53 i, which is the other end of each conductive film linear portion 52 of the meandering resistance element 50, also has the interlayer insulating film 45. It is connected to the thin-film resistance straight line portion 51 facing in the depth direction through a contact portion that penetrates.

  Further, similarly to the first embodiment, the power supply potential VB of the high side circuit portion may be detected by the meandering resistance element 50. In this case, the innermost conductive film layer 11 a of the spiral resistance element 10 and the innermost conductive film linear portion 52 a of the meandering resistance element 50 are electrically connected to the first electrode 40 instead of the second electrode 42. Just connect.

  Further, each conductive film layer 11 of the spiral resistance element 10 and each conductive film linear portion 52 of the meandering pattern of the meandering resistance element 50 may be arranged in different layers (not shown). Thereby, the space | interval between each electrically conductive film layer 11 of the spiral resistance element 10, and the space | interval between each electrically conductive film linear part 52 of the meandering pattern of the meandering resistance element 50 can be narrowed. For this reason, the space | interval between the thin film resistive layers 12 of the spiral resistance element 10 can be narrowed, and it can make it hard to receive the bad influence of an electric charge.

  As described above, according to the second embodiment, the same effect as in the first embodiment can be obtained. Further, according to the second embodiment, by forming the meandering resistance element in the meandering pattern in which the thin film resistance straight line portions and the conductive film straight line portions arranged in different layers are alternately arranged, the arc in FIG. Since the portion 141 and the region corresponding to the arc portion 151 in FIG. 16B can be eliminated, the potential sharing region 143 in FIG. 16A and the region corresponding to the potential sharing region 153 in FIG. . Therefore, according to the second embodiment, the breakdown voltage can be further increased.

(Embodiment 3)
Next, the structure of the semiconductor device according to the third embodiment will be described. FIG. 9 is a plan view showing a planar layout of the breakdown voltage structure of the semiconductor device according to the third embodiment. The semiconductor device according to the third embodiment is different from the semiconductor device according to the second embodiment in the planar layout of each conductive film layer 11 of the spiral resistance element 10. Specifically, each conductive film layer 15 (15a to 15d) disposed in the first breakdown voltage structure portion 3a of the spiral resistance element 10 has a planar layout that is oblique with respect to a direction parallel to the circumferential direction of the spiral resistance element 10. Has been placed.

  And each thin film resistance linear part 61 (61a-61f) of the meandering pattern of the meandering resistance element 60 is parallel along the circumferential direction of the spiral resistance element 10 so as to intersect with each conductive film layer 15 of the spiral resistance element 10. Arranged in a flat layout. The conductive film linear portions 62 (62 a to 62 e) of the meandering pattern of the meandering resistance element 60 are arranged between the conductive film layers 15 of the spiral resistance element 10 in a planar layout parallel to the conductive film layer 15.

  Even when such a meandering resistance element 60 is arranged, the potential difference ΔV between adjacent conductive film layers (the conductive film layers 15 and the conductive film linear portions 62) in the first voltage withstanding structure portion 3a is equal to the embodiment. Similar to 2, 1/10 × V [V].

  As described above, according to the third embodiment, the same effect as in the first and second embodiments can be obtained.

(Embodiment 4)
Next, the structure of the semiconductor device according to the fourth embodiment will be described. FIG. 10 is a plan view showing a planar layout of the breakdown voltage structure of the semiconductor device according to the fourth embodiment. FIG. 11 is a cross-sectional view showing a cross-sectional structure taken along section line GG ′ of FIG. The semiconductor device according to the fourth embodiment is different from the semiconductor device according to the first embodiment in that the spiral resistance element 10 is formed only by the thin-film resistance layer 16 arranged in a spiral planar layout surrounding the periphery of the high potential side region 1. It is the point which constitutes. The positional relationship of the planar layout between the spiral resistance element 10 and the meandering resistance element 20 is the same as in the first embodiment.

  In the fourth embodiment, a third insulating film 47 is further disposed between the second insulating film 44 and the interlayer insulating film 45 as shown in FIG. The thin film resistance layer 16 of the spiral resistance element 10 (reference numerals 16a to 16e in order from the inner circumference side to the outer circumference side is provided inside the third insulating film 47 so as to face the meandering resistance element 20 in the depth direction. A thin film resistor layer 16e is not shown in FIG. The innermost thin film resistance layer 16 of the spiral resistance element 10 is electrically connected to the second electrode 41, and the outermost thin film resistance layer 16 e is electrically connected to the third electrode 42. The cross-sectional structure of the thin film resistance straight line portion 21 of the meandering resistance element 20 is the same as that of the first embodiment.

  FIG. 11 shows a configuration in which the reference potential (emitter potential VS of the IGBT of the upper arm) is detected by the meandering resistance element 20, but the high side is detected by the meandering resistance element 50 as in the first embodiment. The power supply potential VB of the circuit unit may be detected.

  As described above, even if the spiral resistance element 10 and the meandering resistance element 20 are both composed only of the thin film resistance layer (thin film resistance layer 16, thin film resistance linear portion 21), the spiral resistance element 10 and the meandering resistance element 20 are laminated. Can be arranged. Further, similarly to the first embodiment, the potential difference ΔV between the respective conductive film layers (the respective thin film resistance layers 16 and the respective thin film resistance linear portions 21) can be set to 1/5 × V [V].

  As described above, according to the fourth embodiment, the same effect as in the first embodiment can be obtained.

(Embodiment 5)
Next, the structure of the semiconductor device according to the fifth embodiment will be described. FIG. 12 is a plan view showing a planar layout of the breakdown voltage structure of the semiconductor device according to the fifth embodiment. 13 is a cross-sectional view showing a cross-sectional structure taken along the section line XX ′ of FIG. The cross-sectional structures of the cutting line AA ′, the cutting line BB, and the cutting line CC ′ in FIG. 12 are the same as those in the first embodiment. The semiconductor device according to the fifth embodiment is different from the semiconductor device according to the first embodiment in that the meandering resistance element 20 is connected to the gate electrode 74 of, for example, a lateral p-channel MOSFET formed in the low potential side region 2. is there.

  As shown in FIGS. 12 and 13, an n-type diffusion region 71 is provided outside the p-type diffusion region 34 on the front surface layer of the p-type semiconductor substrate 30. The n-type diffusion region 71 is electrically separated from the n-type diffusion regions 32 and 33 by the p-type diffusion region 34 and constitutes the low potential side region 2. In the n-type diffusion region 71, for example, a low-side circuit portion (a CMOS circuit in which a lateral n-channel MOSFET and a lateral p-channel MOSFET are complementarily connected) is disposed. The lateral n-channel MOSFET is not shown.

The lateral p-channel MOSFET has a general planar gate type MOS gate structure including a p ⁺ type drain region 72, a p ⁺ type source region 73, and a gate electrode 74. The fourth electrode 75 is electrically connected via a gate electrode 74 of a lateral p-channel MOSFET via a contact portion 76 that penetrates the interlayer insulating film 45. The fourth electrode 75 is connected to the outermost thin film resistance straight line portion 21 e of the meandering resistance element 20 through the contact portion 17 that penetrates the interlayer insulating film 45.

  Further, the fifth embodiment may be applied to the second to fourth embodiments.

  As described above, according to the fifth embodiment, the same effects as in the first to fourth embodiments can be obtained.

(Embodiment 6)
Next, a circuit configuration example to which the semiconductor device according to the first to fifth embodiments is applied as the semiconductor device according to the sixth embodiment will be described. FIG. 14 is a circuit diagram of a circuit configuration of the semiconductor device according to the sixth embodiment. Here, for example, in the case of driving two IGBTs (Insulated Gate Bipolar Transistors) 221 and 222 constituting one phase of the bridge circuit 220 serving as an output stage, an example is described in which each potential is detected. Explained. The IGBTs 221 and 222 are connected in series between the high voltage power supply Vdc and the ground potential GND. A semiconductor device 200 according to the sixth embodiment shown in FIG. 14 includes a high-side drive circuit 201, a low-side drive circuit 202, a level shift circuit 205, first to fourth terminals 231 to 234, and the resistors described above on the same semiconductor chip. A sex field plate 5 is provided.

  The first terminal 231 is a terminal that supplies the ground potential GND of the semiconductor device 200. The second terminal 232 is a terminal that supplies the power supply voltage Vcc from the voltage power supply 211 to the semiconductor device 210. The third terminal 233 is a terminal that supplies the power supply potential VB of the high-side drive circuit 201. The fourth terminal 234 is a terminal for supplying the emitter potential VS of the IGBT 221 of the upper arm. The power supply potential VB is the sum of the emitter potential VS of the upper arm IGBT 221 and the high-side power supply. The voltage E1 charged in the bootstrap capacitor 213 from the voltage power supply 211 via the bootstrap diode 212 becomes the high side power supply. The emitter potential VS of the upper-arm IGBT 221 is the potential at the connection point 223 between the upper-arm IGBT 221 and the low-potential-side (hereinafter referred to as the lower arm) IGBT 222. The connection point 223 is the output terminal OUT of the bridge circuit 220.

  The high side drive circuit 201 operates at the power supply voltage Vcc with the emitter potential VS of the IGBT 221 of the upper arm as the reference potential and the power supply potential VB as the highest potential. The high side drive circuit 201 drives the IGBT 221 of the upper arm based on the input signal of the level shift circuit 205. The low side drive circuit 202 includes a control circuit 203 and a comparator 204. The low-side drive circuit 202 operates, for example, using the ground potential GND as a reference potential. The control circuit 203 operates with the power supply voltage Vcc supplied from the second terminal 232 with reference to the ground potential GND, and based on the control signal IN from the outside (such as a microcomputer) or the abnormality detection signal from the abnormality detection circuit. Then, the nch MOSFET 206 of the level shift circuit 205 for level up is driven.

  The comparator 204 compares the potential at the intermediate potential point 92a of the sense resistor 92 with a predetermined reference voltage. The output (comparison result) of the comparator 204 is input to the high side drive circuit 201 via the control circuit 203 and the level shift circuit 205. The output of the comparator 204 is input to the driver circuit 214. The driver circuit 214 drives the IGBT 222 of the lower arm. The driver circuit 214 may be disposed on the same semiconductor chip as the semiconductor device 200. The level shift circuit 205 includes a high breakdown voltage nch MOSFET 206 and a level shift resistor 207. The level shift circuit 205 receives the input signal from the low side drive circuit 202 and drives the high side drive circuit 201.

  The resistors 91 and 92 are connected between the fourth terminal 234 and the first terminal 231. The resistor 91 corresponds to the spiral resistance element 10 of the first to fifth embodiments. A connection point 91 a between the fourth terminal 234 and the resistor 91 corresponds to the inner peripheral side end portion 10 a of the spiral resistance element 10. A connection point 91 b between the first terminal 231 and the resistor 91 corresponds to the outer peripheral side end portion 10 b of the spiral resistance element 10. The resistor 92 corresponds to the meandering resistance elements 20, 50, 60 of the first to fifth embodiments. That is, these resistors 91 and 92 correspond to the resistive field plates of the first to fifth embodiments. A resistor (hereinafter referred to as a sense resistor) 92 is a voltage dividing resistor for detecting the emitter potential VS of the IGBT 221 of the upper arm.

  The semiconductor device 200 shown in FIG. 14 detects the emitter potential VS (hereinafter referred to as VS potential) of the IGBT 221 of the upper arm by using the sense resistor 92 as a voltage dividing resistor. When the comparator 204 determines that the VS potential has fallen below the reference voltage, the semiconductor device 200 shown in FIG. 14 gives an alarm or the like, turns off the upper-arm IGBT 221 with the high-side drive circuit 201, The circuit 214 controls to turn off the IGBT 222 of the lower arm.

  As described above, according to the sixth embodiment, the same effects as in the first to fifth embodiments can be obtained.

(Embodiment 7)
Next, a circuit configuration example to which the semiconductor device according to the first to fifth embodiments is applied as the semiconductor device according to the seventh embodiment will be described. FIG. 15 is a circuit diagram of a circuit configuration of the semiconductor device according to the seventh embodiment. The circuit configuration of the semiconductor device 210 according to the seventh embodiment is different from the circuit configuration of the semiconductor device according to the sixth embodiment in that a voltage dividing resistor for detecting the power supply potential VB of the high-side drive circuit 201 is used. A sense resistor (hereinafter referred to as a second sense resistor) 93 is provided. The second sense resistor 93 corresponds to the meandering resistance elements 20, 50, 60 of the first to fifth embodiments. That is, in the seventh embodiment, two meandering resistance elements are provided so as to overlap the conductive film layer of the spiral resistance element via the interlayer insulating film. The two meandering resistance elements may be arranged adjacent to each other or may be arranged apart from each other.

  The second sense resistor 93 is connected between the third terminal 233 and the first terminal 231. In this case, the low-side drive circuit 202 includes a plurality of comparators 204, and the intermediate potential point 92 a of the sense resistor (hereinafter referred to as the first sense resistor) 92 and the intermediate potential point 93 a of the second sense resistor 93 are different from each other. Connected. As in the sixth embodiment, the comparator 204 compares the potential at the intermediate potential point 92a of the first sense resistor 92 with a predetermined reference voltage. The comparator 204 compares the potential at the intermediate potential point 93a of the second sense resistor 93 with a predetermined reference voltage. The comparator 204 compares the voltage between the intermediate potential point 92a of the first sense resistor 92 and the intermediate potential point 93a of the second sense resistor 93 (the voltage E1 of the bootstrap capacitor 213) with a predetermined reference voltage. The output of the comparator 204 is input to the high side drive circuit 201 and the driver circuit 214 as in the sixth embodiment.

  The semiconductor device 210 shown in FIG. 15 detects the divided voltage of the first and second sense resistors 92 and 93 to thereby detect the power supply potential VB (hereinafter referred to as VB potential) of the high-side drive circuit 201 and the IGBT 221 of the upper arm. An emitter potential VS (hereinafter referred to as VS potential) and a voltage between VB potential and VS potential (hereinafter referred to as VB-VS voltage) are detected. When the comparator 204 determines that at least one of the VB potential and the VS potential has fallen below the reference voltage, the semiconductor device 210 illustrated in FIG. The IGBT 221 is turned off, or the driver circuit 214 controls the lower arm IGBT 222 to be turned off. In the semiconductor device 210 shown in FIG. 15, when the comparator 204 determines that the voltage between VB and VS is lower than the reference voltage, the driver circuit 214 increases the pulse width of the on-period of the IGBT 222 of the lower arm to increase the bootstrap. Control to increase the charging time of the capacitor 213 is performed. That is, by disposing the first and second sense resistors 92 and 93, the same function as the level down level shift circuit can be obtained without using the level down level shift circuit.

  As described above, according to the seventh embodiment, the same effects as those of the first to sixth embodiments are obtained.

(Embodiment 8)
Next, the structure of the semiconductor device according to the eighth embodiment will be described. FIG. 20 is a plan view showing a planar layout of the breakdown voltage structure of the semiconductor device according to the eighth embodiment. FIG. 21 is a plan view showing a planar layout of another example of the breakdown voltage structure of the semiconductor device according to the eighth embodiment. 20 and 21 show a planar layout of the entire resistive field plate 5. The semiconductor device according to the eighth embodiment is different from the semiconductor device according to the first embodiment in that one or more spiral resistance elements are further provided in place of the meandering resistance elements. That is, the resistive field plate 5 is composed of only two or more spiral resistance elements having different numbers of spiral lines.

  Here, a case where the resistive field plate 5 is composed of two spiral resistance elements will be described as an example. Specifically, the resistive field plate 5 includes a first spiral resistance element 310 and a second spiral resistance element 320 having a smaller number of spiral lines than the first spiral resistance element 310. The first and second spiral resistance elements 310 are arranged in a spiral planar layout surrounding the periphery of the high potential side region 1 from the high potential side region 1 side to the low potential side region 2 side. The function of the first spiral resistance element 310 is the same as that of the spiral resistance element of the first embodiment. For example, the spiral lines of the first spiral resistance element 310 are arranged at substantially equal intervals with substantially the same width. The reason is the same as in the first embodiment.

  In the first spiral resistance element 310, as in the first embodiment, a conductive layer 311 made of a conductive material such as metal is disposed in the first breakdown voltage structure 3a, and impurities are present in the second breakdown voltage structure 3b. A thin film resistive layer 312 made of a resistive material such as dosed polysilicon is disposed. The conductive film layer 311 of the first spiral resistance element 310 is disposed at a position intersecting with the second spiral resistance element 320 when viewed from the front surface side of the semiconductor chip, as will be described later. Each conductive film layer 311 of the first spiral resistance element 310 has a linear or substantially arc-shaped planar shape along the spiral pattern of the first spiral resistance element 310, and the planar shape and the length thereof are the second spiral. It differs for each intersection with the resistance element 320.

  The second spiral resistance element 320 is disposed in the voltage withstanding structure portion 3 so as to intersect with a part (conductive film layer 311) of the first spiral resistance element 310 when viewed from the front surface side of the semiconductor chip. The second spiral resistance element 320 is disposed, for example, between the innermost spiral line 310c and the outermost spiral line 310d of the first spiral resistance element 310. 20 and 21, in order to clarify each planar layout of the first spiral resistance element 310 and the second spiral resistance element 320, the second spiral resistance element 320 is indicated by a solid line thicker than the first spiral resistance element 10. Show. Further, the conductive film layer 311 of the first spiral resistance element 310 is indicated by a solid line that is thinner than the thin film resistance layer 312 of the first spiral resistance element 310.

  In the second spiral resistance element 320, a thin film resistance layer 321 made of a resistive material such as polysilicon doped with impurities is disposed in the breakdown voltage structure portion 3. The second spiral resistance element 320 is arranged in a different layer from the conductive film layer 311 of the first spiral resistance element 310 in the first breakdown voltage structure portion 3a, and is deep in the conductive film layer 311 with an interlayer insulating film (not shown) interposed therebetween. Opposite direction. The length of the conductive film layer 311 of the first spiral resistance element 310 is such that the thin film resistance layers 312 and 321 of the first and second spiral resistance elements 310 and 320 do not overlap in the depth direction due to variations in the manufacturing process, and Set as short as possible. The second spiral resistance element 320 may be arranged at the same level as the thin film resistance layer 312 of the first spiral resistance element 310.

  The second spiral resistance element 320 is, for example, a sense for detecting the emitter potential VS (VS potential) of the IGBT 221 of the upper arm and the power supply potential VB of the high-side drive circuit 201, similarly to the meandering resistance element of the first embodiment. Used as resistors 92 and 93 (see FIGS. 14 and 15). What is necessary is just to draw out the electric potential used as the intermediate electric potential points 92a and 93a of the sense resistances 92 and 93 from the predetermined electric potential point 320c by the side of the outer side edge part 320b which applies the minimum electric potential of the 2nd spiral resistance element 320, for example.

  Further, the first and second spiral resistance elements 310 and 320 are preferably arranged so as not to cause a potential difference between the potential distribution generated by the first spiral resistance element 310 and the potential distribution generated by the second spiral resistance element 320. . That is, it is preferable that the second spiral resistance element 320 is arranged in a planar layout so as to have substantially the same potential as that of the conductive film layer 311 at a location where the second spiral resistance element 310 intersects. Thereby, local electric field concentration can be prevented from occurring in the first and second spiral resistance elements 310 and 320.

  Specifically, for example, the inner ends 310a and 320a to which the highest potentials of the first and second spiral resistance elements 310 and 320 are applied are arranged close to each other, and the lowest potentials of the first and second spiral resistance elements 310 and 320 are disposed. The outer end portions 310b and 320b to which the voltage is applied are arranged close to each other. The potential difference from the inner end portion 320 a of the second spiral resistance element 320 to the intersection of the first and second spiral resistance elements 310 and 320 is equal to the same potential difference from the inner end portion 310 a of the first spiral resistance element 310. In addition, the second spiral resistance element 320 may be disposed.

  By arranging the second spiral resistance element 320 in this way, it is only necessary to design the winding width and the interval between the windings so that the first and second spiral resistance elements 310 and 320 have an equal potential distribution. The potential difference at the location where the first spiral resistance element 310 and the second spiral resistance element 320 intersect can be eliminated. The inner ends 310a and 320a of the first and second spiral resistance elements 310 and 320 may be in contact with each other. The outer end portions 310b and 320b of the first and second spiral resistance elements 310 and 320 may be in contact with each other.

  The number of turns of the second spiral resistance element 320 (the number of spiral lines) can be variously changed. For example, the number of turns of the spiral of the second spiral resistance element 320 is determined by, for example, a response time when detecting a predetermined voltage value. Further, the number of turns of the spiral of the second spiral resistance element 320 is such that the resistance value and the parasitic capacitance associated with the resistance value are reduced to some extent to the extent that they can be used as the sense resistors 92 and 93 as described above, and The resistance value is set to be large enough that the current (consumption current) consumed by the second spiral resistance element 320 can be suppressed to a predetermined value or less. The potential distribution of the first and second spiral resistance elements 310 and 320 only needs to be uniform, and the spiral direction of the second spiral resistance element 320 is the same as the spiral direction of the first spiral resistance element 310. It may be reverse.

  For example, in FIG. 20, the number of spiral turns of the first spiral resistance element 310 is eight, and the number of spiral turns of the second spiral resistance element 320 is one round in the same circumferential direction as the first spiral resistance element 310. A case where the number of spiral lines is one and the first spiral resistance element 310 and the second spiral resistance element 320 intersect at six locations is shown. In this case, the first spiral resistance element 310 has six conductive film layers 311. Each conductive film layer 311 of the first spiral resistance element 310 is disposed, for example, on each spiral line except the innermost and outermost spiral lines of the first spiral resistance element 310, and the first spiral resistance element 310 has a spiral first shape. It is dotted along the two spiral resistance elements 320. These six conductive film layers 311 are respectively given reference numerals 311a to 311f in order from the inner circumference side toward the outer circumference side. Reference numerals 313a to 313f are attached in order from the inner peripheral side to the outer peripheral side of the contact portions between the respective one ends of the conductive film layer 311 and the thin film resistance layer 312. The contact portions between the other end of the conductive film layer 311 and the thin-film resistance layer 312 are given 314a to 314f in order from the inner peripheral side to the outer peripheral side.

  Further, the number of turns of the spiral of the second spiral resistance element 320 may be one or more (not shown), and may be less than one. When the number of turns of the spiral line of the second spiral resistance element 320 is, for example, 1/2, the second spiral resistance element 320 is arranged in, for example, an arcuate planar layout (not shown). Further, when the number of turns of the spiral of the second spiral resistance element 320 is, for example, 1/4, the second spiral resistance element 320 is arranged in, for example, a linear planar layout as in another example shown in FIG. May be.

  In FIG. 21, as another example, the number of spiral turns of the first spiral resistance element 310 is 8, and the number of spiral turns of the second spiral resistance element 320 is 1/4, and the first spiral resistance The case where the element 310 and the second spiral resistance element 320 intersect at seven points is shown. In this case, the second spiral resistance element 320 is disposed so as to be inclined with respect to the circumferential direction of the spiral line of the first spiral resistance element 310, and the innermost and outermost spirals of the first spiral resistance element 310 are arranged. It is arranged to pass through all the other spiral lines except the line. The first spiral resistance element 310 has seven conductive film layers 311. These seven conductive film layers 311 are arranged, for example, one on each spiral line excluding the innermost and outermost spiral lines of the first spiral resistance element 310, and the second spiral resistance element 320 is linear. Dotted along.

  Reference numerals 311a to 311g are attached to the seven conductive film layers 311 in FIG. 21 in order from the inner peripheral side to the outer peripheral side. Reference numerals 313a to 313g are attached in order from the inner peripheral side to the outer peripheral side of contact portions between the respective one ends of the conductive film layer 311 and the thin film resistance layer 312. The contact portions between the other end of the conductive film layer 311 and the thin-film resistance layer 312 are given 314a to 314g in order from the inner peripheral side to the outer peripheral side. In another example shown in FIG. 21, the inner end portion 310a and the outer end portion 310b of the first spiral resistance element 310 are close to the inner end portion 320a and the outer end portion 320b of the second spiral resistance element 320, respectively. In the portion where the second spiral resistance element 320 is extended, the number of spiral lines facing the first spiral resistance element 310 is nine.

  For example, the number of turns of the spiral of the first spiral resistance element 310, the width of the spiral, and the interval between the spirals are determined so that the breakdown voltage and reliability required in the breakdown voltage structure 3 can be obtained. The number of turns of the spiral of the second spiral resistance element 320 is the width of the breakdown voltage structure 3 (width in the direction from the inside to the outside), the circuit configuration of the high side circuit portion disposed in the high potential side region 1, and It is determined by the dose amount (resistance value) of the thin-film resistance layer 321 constituting the second spiral resistance element 320. The width of the spiral line of the second spiral resistance element 320 and the interval between the spiral lines may be different from those of the first spiral resistance element 310. Further, when the resistive field plate 5 is composed of two or more spiral resistance elements, a part of one spiral resistance element may be a conductive film layer at a portion where the spiral resistance elements intersect each other.

Next, the cross-sectional structure of the semiconductor device according to the eighth embodiment will be described using the cross-sectional structure taken along the cutting line HH ′ in FIG. 21 as an example. 22 is a cross-sectional view showing a cross-sectional structure taken along the cutting line HH ′ of FIG. Here, a cutting line H passing through the conductive film layer 311c that is parallel to the direction from the inner circumference side to the outer circumference side of the first spiral resistance element 310 and that is disposed in the spiral line of the third round of the first spiral resistance element 310 is shown. A cross-sectional structure of −H ′ will be described as an example. As shown in FIG. 22, the thin film resistance layer 312 of the first spiral resistance element 310 is formed in the interlayer insulating film 45 that covers the n-type diffusion region 33 between the n ⁺ -type region 35 and the p ⁺ -type region 39. Is provided.

Further, the second insulating layer 45 of the first spiral resistance element 310 is separated from the thin film resistance layer 312 of the first spiral resistance element 310 inside the interlayer insulating film 45 covering the n-type diffusion region 33 between the n ⁺ -type region 35 and the p ⁺ -type region 39. A thin film resistance layer 321 of the spiral resistance element 320 is disposed. The thin-film resistance layer 321 of the second spiral resistance element 320 is the third (third-turn spiral line) thin-film resistance layer 312 from the inner side (first electrode 40 side) of the first spiral resistance element 310 (first winding 40). Adjacent to the second electrode 42 side). Inside the interlayer insulating film 46, a conductive film layer 311 (first conductive film layer 311c is shown in FIG. 22) of the first spiral resistance element 310 is provided. The conductive film layer 311 of the first spiral resistance element 310 faces the thin film resistance layer 321 of the second spiral resistance element 320 in the depth direction with the interlayer insulating film 46 interposed therebetween. That is, in the first breakdown voltage structure 3 a (cross section taken along the cutting line HH ′), the first and second spiral resistance elements 310 and 320 have the thin film resistance layers 312 and 321 as the first layer, and the first spiral resistance element 310. A field plate having a second conductive film layer 11 is formed.

  The innermost thin film resistance layer 312 (first electrode 40 side) of the first spiral resistance element 310 is electrically connected to the first electrode 40, and the outermost thin film resistance layer 312 (second electrode 42 side) is the first thin film resistance layer 312. The two electrodes 42 are electrically connected. Of the thin film resistance layer 312 of the first spiral resistance element 310, the three thin film resistance layers 312 inside the thin film resistance layer 321 of the second spiral resistance element 320 are electrically connected to each other. Out of these three thin film resistance layers 312, the outermost thin film resistance layer 312 is electrically connected to the conductive film layer 311 c of the first spiral resistance element 310. Among the thin film resistance layers 312 of the first spiral resistance element 310, the five thin film resistance layers 312 outside the thin film resistance layer 321 of the second spiral resistance element 320 are electrically connected. Among these five thin film resistance layers 312, the innermost thin film resistance layer 312 is electrically connected to the conductive film layer 311c of the first spiral resistance element 310.

  Although not shown in the drawings, the cross-sectional structure taken along a cutting line passing through the conductive film layers 311a, 311b, 311d to 311g (see FIG. 21) other than the conductive film layer 311c of the first spiral resistance element 310 is different in the following two points. Except for this, the cross-sectional structure is the same as that shown in FIG. The first difference is that the positions of the other conductive film layers 311a, 311b, 311d-311g between the first and second electrodes 40, 42 are different. The second difference is that the thin film resistance layer 321 of the second spiral resistance element 320 is disposed at a position facing the other conductive film layers 311a, 311b, 311d to 311g in the depth direction, and the thin film resistance layer 321 is arranged. The number of thin film resistance layers 312 of the first spiral resistance element 310 disposed on the inner side and the outer side (the number of turns) is different.

  In other words, the more the conductive film layer 311 (311a, 311b, 311d to 311g) is arranged in the spiral on the inner peripheral side of the first spiral resistance element 310, the first arranged in the inner side of the conductive film layer 311. The number of thin film resistance layers 312 of the spiral resistance element 310 is small, and the number of thin film resistance layers 312 of the first spiral resistance element 310 disposed outside the conductive film layer 311 is large. Specifically, the number of the thin-film resistance layers 312 of the first spiral resistance element 310 disposed inside the conductive film layer 311a (see FIG. 21) of the first spiral resistance element 310 is one, and the conductive film The number of the thin-film resistance layers 312 of the first spiral resistance element 310 disposed on the inner side of the layer 311a is seven.

  20, even when arranged in a planar layout, the cross section taken along the cutting line passing through each of the conductive film layers 311a to 311f of the first spiral resistance element 310 is the circumference of the spiral line of the first spiral resistance element 310. Except for the number of times and the above two points, the cross-sectional structure is the same as that shown in FIG.

  The configuration other than the arrangement of the conductive film layer 311 and the thin film resistance layer 312 of the first spiral resistance element 310 and the thin film resistance layer 321 of the second spiral resistance element 320 in the cross-sectional structure of the semiconductor device according to the eighth embodiment is as follows. This is the same as Embodiment 1 (see FIG. 3).

  Further, the fourth embodiment (see FIG. 11) may be applied to the eighth embodiment, and all the spiral resistance elements constituting the resistive field plate 5 may be composed of only a thin film resistance layer. In this case, an upper layer spiral resistance element having a different number of turns of the spiral resistance element and the spiral line may be arranged in multiple layers (multiple) via the insulating film on the lower layer spiral resistance element.

  As described above, according to the eighth embodiment, even when the resistive field plate is configured by only the spiral resistance element, the same effects as those of the first to seventh embodiments are obtained.

(Embodiment 9)
Next, a cross-sectional structure of the semiconductor device according to the ninth embodiment will be described. 23 to 25 are sectional views showing an example of the structure of the semiconductor device according to the ninth embodiment. 23 to 25 show a cross-sectional structure taken along the cutting line HH ′ of FIG. The semiconductor device according to the ninth embodiment differs from the semiconductor device according to the eighth embodiment in the configuration of each region inside the p-type semiconductor substrate 30. The arrangement of the first and second spiral resistance elements 310 and 320 and each electrode on the p-type semiconductor substrate 30 is the same as in the eighth embodiment. Hereinafter, the cross-sectional structures shown in FIGS.

  Specifically, in the first cross-sectional structure example shown in FIG. 23, the p-type semiconductor substrate 30 is an epitaxial substrate in which a p-type epitaxial growth layer 332 is stacked on the surface of a p-type starting substrate 331. In this case, the p-type epitaxial growth layer 332 functions as a p-type well region in which the low potential side region 2 is formed. For this reason, the p-type diffusion region 34 may not be provided. However, when the p-type diffusion region 34 is provided, the p-type diffusion region 34 is formed on the p-type semiconductor substrate 30 as indicated by a dotted line in FIG. The p-type epitaxial growth layer 332 is penetrated from the front surface and reaches the p-type starting substrate 331.

The n ⁻ type diffusion region 333 is provided inside the p type epitaxial growth layer 332 and reaches the p type starting substrate 331 from the front surface of the p type semiconductor substrate 30. The n ⁻ -type diffusion region 333 faces the thin film resistance layers 312 and 321 of the first and second spiral resistance elements 310 and 320 in the depth direction with the first insulating film 43 and the interlayer insulating film 45 interposed therebetween. Parasitic diode 4 is formed at the pn junction between p-type diffusion region 34 (p-type epitaxial growth layer 332 if no p-type diffusion region 34 is provided) and n ⁻ -type diffusion region 333. The n ⁻ type diffusion region 333 constitutes the breakdown voltage structure 3. The n ⁻ -type diffusion region 333 is a region where most of the depletion layer expands when a reverse bias is applied to the parasitic diode 4, and this region is a breakdown voltage region.

The n-type diffusion region 32 constituting the high potential side region 1 is provided inside the p-type epitaxial growth layer 332 inside the thin-film resistance layer 312 of the first spiral resistance element 310, Reach a certain depth from the surface. An n-type buried layer 334 is provided between the n-type diffusion region 32 and the p-type starting substrate 331. The n-type buried layer 334 is in contact with the n-type diffusion region 32 and the p-type starting substrate 331. N type diffusion region 32 and n type buried layer 334 are in contact with n ⁻ type diffusion region 333. The n ⁻ -type diffusion region 333 may be extended to the inside of the thin-film resistance layer 312 of the first spiral resistance element 310 without providing the n-type diffusion region 32.

Also, as in the second cross-sectional structure example shown in FIG. 24, the p-type semiconductor substrate 30 may be an epitaxial substrate in which an n ⁻ -type epitaxial growth layer 341 is stacked on the surface of the p-type starting substrate 331. In this case, the n-type diffusion region 32 is provided inside the n ⁻ -type epitaxial growth layer 341 inside the thin-film resistance layer 312 of the first spiral resistance element 310 and is predetermined from the front surface of the p-type semiconductor substrate 30. Reach the depth of. An n-type buried layer 334 is provided between the n-type diffusion region 32 and the p-type starting substrate 331 as in the first cross-sectional structure example of FIG.

The p-type diffusion region 34 reaches the p-type starting substrate 331 through the n ⁻ -type epitaxial growth layer 341 from the front surface of the p-type semiconductor substrate 30. A parasitic diode 4 is formed at the pn junction between the p-type diffusion region 34 and the n ⁻ -type epitaxial growth layer 341. The p-type diffusion region 34 functions as a p-type well region in which the low potential side region 2 is formed. The n ⁻ type epitaxial growth layer 341 has a breakdown voltage structure at a portion facing the thin film resistance layers 312 and 321 of the first and second spiral resistance elements 310 and 320 in the depth direction with the first insulating film 43 and the interlayer insulating film 45 interposed therebetween. Part 3 is configured.

  25, the p-type semiconductor substrate 30 may be an epitaxial substrate in which an n-type epitaxial growth layer 342 is stacked on the surface of a p-type starting substrate 331. In this case, the n-type diffusion region constituting the high potential side region 1 is not provided. The n-type buried layer 334 is provided between the n-type epitaxial growth layer 342 and the p-type starting substrate 331 inside the thin-film resistance layer 312 of the first spiral resistance element 310. The n-type epitaxial growth layer 342 constitutes the high potential region 1 inside the thin film resistance layer 312 of the first spiral resistance element 310.

  The p-type diffusion region 34 reaches the p-type starting substrate 331 through the n-type epitaxial growth layer 342 from the front surface of the p-type semiconductor substrate 30. A parasitic diode 4 is formed at the pn junction between the p-type diffusion region 34 and the n-type epitaxial growth layer 342. The p-type diffusion region 34 functions as a p-type well region in which the low potential side region 2 is formed. The n-type epitaxial growth layer 342 has a breakdown voltage structure portion at a portion facing the thin film resistance layers 312 and 321 of the first and second spiral resistance elements 310 and 320 in the depth direction across the first insulating film 43 and the interlayer insulating film 45. 3 is configured.

  The ninth embodiment may be applied to the breakdown voltage structure of the semiconductor device according to the eighth embodiment arranged in the planar layout shown in FIG.

  As described above, according to the ninth embodiment, even when the cross-sectional structure of each region (semiconductor region constituting the parasitic diode of the breakdown voltage structure) inside the p-type semiconductor substrate is different, the first embodiment The same effect as ~ 8 is produced.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the case where the meandering resistance element is used as the sense resistance is described as an example. However, the present invention is not limited to the case where the meandering resistance element is used as the sense resistance. It is applicable to various configurations. In each of the above-described embodiments, the case where the meandering resistance element is used as the sense resistance has been described as an example. However, the spiral resistance element may be used as the sense resistance. Further, the same effect can be obtained when a resistance element arranged in a linear planar layout is arranged to face the spiral resistance element in the depth direction with an interlayer insulating film interposed therebetween instead of the meandering resistance element. In each of the above-described embodiments, the case where the VB potential, the VS potential, and the VB-VS voltage are detected has been described as an example. However, the present invention is not limited to this. The voltage can be detected. In addition to the first and second sense resistors, a sense resistor for detecting another potential / voltage may be arranged. Further, in each of the above-described embodiments, the first conductivity type is n-type and the second conductivity type is p-type. However, in the present invention, the first conductivity type is p-type and the second conductivity type is n-type. The same holds true.

  As described above, the semiconductor device according to the present invention is useful for a power semiconductor device used in a power conversion device, a power supply device such as various industrial machines, and the like.

DESCRIPTION OF SYMBOLS 1 High electric potential side area | region 2 Low electric potential side area | region 3 Withstand voltage | pressure structure part 3a 1st withstand voltage structure part 3b 2nd withstand voltage structure part 4 Parasitic diode 5 Resistive field plate 10,310,320 Spiral resistance element 10a, 10b, 310a, 310b, 320a, 320b End portions 11, 11a to 11d, 15, 16, 16a to 16e, 311, 311a to 311g of the spiral resistance elements 12, 12a to 12e Thin film resistance layers 13a to 13e of the spiral resistance elements , 14a-14d, 17, 76, 313a-313g, 314a-314g Contact part 20, 50, 60 Meander resistance element 20a, 20b, 50a, 50b End of meander resistance element 21, 21a-21f, 51, 51a-51f , 61, 61a to 61f Thin film resistance linear portions 22a to 22f of the meandering resistance element , P-type region 32,33,71 n-type diffusion region 34 p-type diffusion region 35 n ⁺ -type region of the turning point 23a~23d intersection 30 p-type semiconductor substrate 31 substrate back surface side of the serpentine pattern of 53a~53j serpentine resistance element 36, 38 p-type region 37, 39 p ⁺ -type region 40-42, 75 Electrode 43, 44, 46 Insulating film 45, 46 Interlayer insulating film 52, 52a-52e, 62, 62a-62e Conductive film straight line of meandering resistance element Portion 72 p ⁺ -type drain region 73 p ⁺ -type source region 74 Gate electrode 91 Resistance 91a Connection point between the fourth terminal and the resistor 91b Connection point between the first terminal and the resistor 92, 93 Sense resistance 92a, 93a Middle of the sense resistance Potential point 201 High-side drive circuit 202 Low-side drive circuit 203 Control circuit 204 Comparator 205 Level shift circuit 206 chMOSFET
207 Level shift resistor 210 Semiconductor device 211 Voltage power supply 212 Bootstrap diode 213 Bootstrap capacitor 214 Driver circuit 220 Bridge circuit 221, 222 IGBT
223 Connection point between IGBT of upper arm and IGBT of lower arm 231 to 234 Terminal 320c Potential point for drawing intermediate potential of sense resistor 331 p-type starting substrate 332 p-type epitaxial growth layer 333 n ^- type diffusion region 334 n-type buried layer 341 n ⁻ type epitaxial growth layer 342 n type epitaxial growth layer GND Ground potential IN Control signal OUT output VB power supply potential Vcc power supply voltage VS Emitter potential of IGBT of upper arm

Claims (15)

A first resistance element provided inside an insulating film on a semiconductor substrate;
A second resistance element provided inside the insulating film and facing the first resistance element in a depth direction across the insulating film;
With
The first resistance element has a part that is different in hierarchy and material and has a continuous part other than the part,
The semiconductor device according to claim 1, wherein the second resistance element is opposed to the part of the first resistance element in a depth direction.   2. The semiconductor device according to claim 1, wherein a conductive film layer is disposed on the part of the first resistance element, and a thin film resistance layer is disposed on a part other than the part. A second semiconductor region provided on the semiconductor substrate and fixed at a lower potential than the first semiconductor region;
A withstand voltage region provided between the first semiconductor region and the second semiconductor region and electrically separating the first semiconductor region and the second semiconductor region;
Further comprising
3. The semiconductor device according to claim 1, wherein the first resistance element is arranged in a spiral planar layout surrounding the periphery of the first semiconductor region in the breakdown voltage region.   4. The semiconductor device according to claim 3, wherein the second resistance elements are arranged in a meandering plane layout.   The semiconductor device according to claim 3, wherein the second resistance element is arranged in a spiral planar layout having a different number of turns than the first resistance element. A second semiconductor region provided on the semiconductor substrate and fixed at a lower potential than the first semiconductor region;
A withstand voltage region provided between the first semiconductor region and the second semiconductor region and electrically separating the first semiconductor region and the second semiconductor region;
A first resistance element disposed in a spiral planar layout surrounding the periphery of the first semiconductor region in the breakdown voltage region;
A second resistance element arranged in a meandering plane layout or a spiral plane layout having a different frequency from the first resistance element, facing a part of the first resistance element in the depth direction with an insulating film interposed therebetween When,
A semiconductor device comprising:   The semiconductor device according to claim 6, wherein the first resistance element is a thin film resistance layer.   The semiconductor device according to claim 6, wherein the first resistance element includes a conductive film layer disposed in a part thereof and a thin film resistance layer disposed in a part other than the part. The second resistance element is arranged in a meandering plane layout;
The semiconductor device according to any one of claims 4 to 8, wherein a turning point of the meandering pattern of the second resistance element is located at a center between adjacent spiral lines of the first resistance element. The second resistance element is arranged in a meandering plane layout;
9. The semiconductor device according to claim 4, wherein a turn point of the meandering pattern of the second resistance element is located on a spiral line of the first resistance element.   The semiconductor device according to claim 1, wherein the second resistance element is a thin film resistance layer.   The semiconductor device according to claim 1, wherein the second resistance element is arranged on the same level as a portion other than the part of the first resistance element.   The semiconductor device according to claim 1, wherein the second resistance element is arranged at a different level from the first resistance element. The second resistance element is arranged in a meandering plane layout;
10. The semiconductor device according to claim 4, wherein the second resistance element has thin film resistance layers and conductive film layers arranged alternately with a meandering pattern folding point interposed therebetween.   The semiconductor device according to claim 1, wherein both ends of the first resistance element and the second resistance element are located in the first semiconductor region and the second semiconductor region, respectively.

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