Semiconductor die and corresponding method

Abstract

The invention relates to a semiconductor die and a corresponding method. The present disclosure relates to a semiconductor die comprising: a first diode chain having a number n1 of diode junctions connected in series, where n1 > = 1; a second diode chain having a number n2 of diode junctions connected in series, where n2 > = 1; the first diode chain and the second diode chain are used for being biased with the same current as a temperature sensor, wherein the first diode chain and the second diode chain differ from each other in terms of the corresponding number n1, n2 of the junctions thereof and / or in terms of the doping concentration of at least one of the junctions.

Description

Technical Field

[0001] The present disclosure relates to semiconductor dies and methods for measuring temperature in a semiconductor die. Background Art

[0002] For development and testing purposes, such as for studying new device designs or layouts, it may be of interest to measure the temperature in a semiconductor die. Additionally, temperature monitoring can also be implemented, for example, in applications to ensure high reliability and safety features, such as in automotive and industrial applications. Over-temperature protection can be used, for example, to prevent overloads and slow (high inductance) short circuits. Summary of the Invention

[0003] Examples of the present application relate to a semiconductor die for temperature sensing.

[0004] In an embodiment, the semiconductor die includes: a first diode chain having a number n 1 of diode junctions connected in series, n 1 ≥ 1; and a second diode chain having a number n 2 of diode junctions connected in series, n 2 ≥ 1. The diode chains differ from each other in at least one of the following aspects: the respective numbers n 1 、n 2 of their junctions; or in terms of the doping concentration of at least one of the junctions. Providing two diode chains to be biased in parallel allows for differential readout, where different numbers and / or doping of the junctions result in different forward voltages. The voltage difference between the diode chains will depend on temperature and vice versa, and can be used to probe the temperature value, as detailed below.

[0005] Specific embodiments and features are provided in this description and the drawings and in the dependent claims. Among them, independent of the specific claim types, individual features will be disclosed. The present disclosure relates to aspects of devices and apparatuses, and also to aspects of methods and uses. If, for example, a specific way of sensing temperature is described, this may relate to the corresponding method of measuring temperature and also to a semiconductor die or system configured for such measurement. Generally, the solution of the present application is to provide a semiconductor die having first and second diode chains, where these diode chains are configured such that different forward voltages are caused when the same current passes through the chains.

[0006] A corresponding "diode chain" includes at least one diode junction or a plurality of diode junctions connected in series. In the case where the first and second diode chains differ in the number of their junctions, by definition, in the second chain, the number can be lower (in the sense of consistent terminology). The second diode chain may include at least one junction, for example, exactly one junction, while the first diode chain may include at least two junctions, where n 1 ≠ n2 。

[0007] The use of first and second diode chains connected in parallel, for example, in a die or in a measurement system, can reduce or even eliminate the influence of parasitic resistance elements. For example, due to the intrinsic nature of the junction, a single diode chain can also have a temperature-dependent voltage drop and can be used for temperature sensing. Since this measurement is based on the intrinsic nature of the junction, it may be relatively stable considering process variations. However, parasitic resistance elements in the circuit can affect the accuracy of a sensor with a single diode chain because the resistance elements themselves can have temperature dependence (increasing the diode area may increase its relative contribution in the I-V characteristic, but it will cost area).

[0008] Compared with using, for example, bipolar transistors located within a bulk material for temperature sensing, diode chains can facilitate integration in a die. Depending on their detailed design, they may require a smaller active device area or even no active device area compared to bipolar transistors processed in the semiconductor body of a die. In addition, bipolar devices may not be available in every technology, particularly in high-voltage or discrete power switch applications. In this regard, the present solution can allow for the simplicity of combining diodes with the possibility of differential readout or system.

[0009] Assuming first and second diode chains, one of which has an additional diode D 2 ,the voltage difference can be calculated as

[0010] V diff =V D2 =V f,0 -k T (T - T 0 ) Equation 1.

[0011] When the diode chains are biased with the same current, the difference in the voltages of the two chains is determined by the additional diode D 2 because the terms or contributions caused by similar elements in the two chains cancel out. More generally, one can directly measure the forward voltage caused by the difference between the chains, for example, the forward voltage of one or more junctions where the chains are different (e.g., in doping and / or quantity). In other words, due to the relative or differential scheme, any resistance contribution can be substantially canceled out, and only the remaining differences based on the number of junctions and / or doping are measured. For example, compared with a single chain, the present sensing system or method can improve accuracy while reducing material or integration effort compared with integrated bipolar devices, for example.

[0012] In an embodiment, a first resistance R 1 of the first diode chain and a second resistance R 2Are substantially equal in size, for example, differing by no more than 10%, 5%, or 3%. In particular, with the technical accuracy commonly used, the resistances R 1 and R 2 can be equal. By having substantially the same series resistance in both chains, the effects caused by the series resistance can be canceled out, so that the difference in voltage is given solely by the properties of the diode(s). For illustration, assume n 1 = 3 and n 2 = 1, the voltage difference can be calculated as

[0013] V diff = 2 * V D = 2 * V f,0 - 2 * k T (T - T 0 ) Equation 2.

[0014] In addition to the junctions, the second diode chain may also include, for example, one or more n and p stripes to mimic the series resistance of the first diode chain and even potentially mimic the contact resistance of the first diode chain, as detailed below. Instead of or in addition to the alignment of the first and second resistors, the corresponding conductor line resistances R M can be aligned so that the conductor lines provided for contacting the first and second diode chains have substantially the same resistance (with a deviation of no more than 10%, 5%, or 3%).

[0015] In an embodiment, the first semiconductor region having the first chain and the second semiconductor region having the second diode chain have the same length L. In particular, this can even apply when the first and second diode chains have different numbers of junctions (n 1 ≠ n 2 ), where having the same length can, for example, allow for the same resistance. The length L can be obtained respectively in the length direction (e.g., the direction of current flow), in which the junctions of the corresponding diode chains are connected in series.

[0016] In an embodiment, the first diode chain has a plurality of first bands, and the second diode chain has at least one first band, where the number of first bands in the diode chains is different. However, the total length L 11 of the plurality of first bands of the first diode chain is equal to the total length L 21 of the at least one first band of the second diode chain. Having substantially the same total length of the first bands in each diode chain can result in substantially the same resistance of the corresponding first bands in the two diode chains. Generally, in the present disclosure, the first doping type can particularly be the n-type.

[0017] In an embodiment, the first diode chain has a plurality of second bands, and the second diode chain has at least one second band, wherein the number of second bands in the diode chains is different. However, the total length L of the plurality of second bands of the first diode chain 12 is equal to the total length L of the at least one second band of the second diode chain 22 . Having substantially the same total length of the second bands in each diode chain can result in substantially the same resistance of the second bands in the two diode chains. Generally, in the present disclosure, the second doping type can be, for example, p-type.

[0018] A diode chain having at least two junctions connected in series can include, for example, a plurality of first bands and second bands alternately arranged along the length direction. For example, for obtaining a series connection of diodes having the same orientation, each second junction can be bridged by a conductive bridge in a metallization layer above, for example. In an embodiment, the first and second diode chains are different in terms of the number of their junctions, but have the same number of conductive bridges between the first and second bands. Even considering the contact resistance, such as the metal-semiconductor contact resistance, having the same number of conductive bridges can allow the adjustment of the same resistance in the chain.

[0019] For illustration, assume that the number of junctions n of the first diode chain 1 is greater than the number of junctions n of the second diode chain 2 , n 1 > n 2 , the first diode chain can include (n 1 –1) conductive bridges connecting the junctions in series. Then, even a smaller amount (n 2 –1) of metal bridges would be sufficient for the series connection of a smaller number n 2 of junctions, the second diode chain can be provided with the same number (n 1 –1) of metal bridges to align the contact resistance.

[0020] In an embodiment, the semiconductor die further includes semiconductor devices. On a first side of the semiconductor body, the semiconductor device can have a load terminal, such as a source region. On the first side, which can also be regarded as the front side, the contact structure of the device can be arranged, such as a contact plate (e.g., a source plate). For example, on an insulating layer arranged on the first side of the semiconductor body, the contact structure can include at least one metallization layer. The semiconductor body can include a semiconductor substrate and, for example, at least one epitaxial layer. Generally, one diode chain or a plurality of diode chains can be integrated in the semiconductor body, for example, integrated in the epitaxial layer, particularly integrated in the topmost epitaxial layer forming the first side of the semiconductor body.

[0021] However, in a particular embodiment, one or more diode chains are arranged on a first side of a semiconductor body, in particular on an insulating layer placed on the first side of the semiconductor body. Placing the diode chain above the semiconductor body allows the sensor to be placed in the active region of the device without significantly affecting the functionality or reducing the semiconductor area available for the device. In other words, the device does not have to be interrupted in order to place the diode chain laterally inside the active region, which may also be the case for temperature measurements (an interruption of the device may distort the temperature profile).

[0022] In addition to the (first) load terminal on the first side of the semiconductor body, the device may include a second load terminal, such as a drain region. Depending on the type of device, for example in the case of a lateral device, the second load terminal may also be arranged on the first side of the semiconductor body. Alternatively, it may be arranged on a second side of the semiconductor body that is vertically opposite to the first side. In addition to the load terminals, the device may include a control terminal (e.g., a gate region) to control the current flow between the load terminals. Generally, the device may be a bipolar or IGBT device (having, for example, an emitter and a collector), a JFET, and / or a transistor device having source and drain regions.

[0023] In an embodiment, the first and second diode chains are respectively formed in a polysilicon layer arranged on the first side of the semiconductor body. Specifically, the polysilicon layer may be deposited, for example, on an insulating layer arranged on the first side of the semiconductor body. In the polysilicon layer, the first and second bands may be formed by doping, for example, an n-band and a p-band alternately arranged in the respective diode chains, as described above. In a conductive layer (in particular, a metallization layer) above the polysilicon layer, a conductive bridge inside each diode chain and / or a conductor line for connecting to each diode chain may be formed.

[0024] In an embodiment, together with the semiconductor device, the diode chain is arranged in the active region of the semiconductor die. Seen in a vertical top view, the active region may be surrounded by an edge termination structure. Seen in a respective vertical cross-section perpendicular to the respective lateral edge of the die, the edge termination structure is arranged laterally between the active region and the respective lateral edge of the die. For example, depending on the required current capability, the active region may be filled with a plurality of device elements connected in parallel.

[0025] In an embodiment, the first and second diode chains may be arranged closer to the center compared to the edges of the active region. This relates to a vertical top view, where the center is the geometric center of the active region. In the case where the first and / or second diode chains have a non-negligible lateral extension with respect to the active region, the center of the respective semiconductor region (the first region in the case of the first diode chain and the second region in the case of the second diode chain) may be considered for comparing the position of the respective diode chain with the center of the active region.

[0026] Independent of a specific position relative to the center of the active region, the diode chains can be placed rather close to each other. Referring, for example, to the average lateral width of the active region - which can be taken as the average of its minimum and maximum extensions obtained respectively along a line passing through the center of the active region, the first and second diode chains can be placed, for example, at a lateral distance not exceeding 50%, 40%, 30% or 20% of this lateral width. Specifically, the distance between the first and second diode chains can be taken as the lateral distance between their centers (the centers of the respective first and second semiconductor regions, see above).

[0027] In an embodiment, the first and second diode chains can be arranged on a common isotherm. Independent of a specific distance between the diode chains, the temperature on the isotherm can be the same. The specific temperature value can depend on the device characteristics and its operation during use. However, the temperature distribution (e.g., the relative temperature profile across the device) can be defined by the device geometry (e.g., the size and shape of the active region).

[0028] The contact structure of the semiconductor device can particularly include contact pads (load pads) in the top metallization layer, such as source plates. In an embodiment, via conductor lines in a wiring layer arranged below the top metallization layer, the first and second diode chains are respectively connected. Specifically, these conductor lines can extend below the contact pads (source plates), that is, be covered by the contact pads. In other words, the top metallization layer should not be interrupted for contacting the diode chains, for example because differential schemes eliminating resistance elements allow for smaller / thinner conductor lines with higher resistance.

[0029] Generally, the top metallization layer can be the only metallization layer of the contact structure. Alternatively, the contact structure can include one or several metallization layers below the top metallization layer, for example for wiring the control terminals of the device. The conductor lines connected to the diode chains can be formed in such metallization layers, or alternatively, for example, formed in a polysilicon layer.

[0030] In an embodiment, a system for measuring a temperature value includes a semiconductor die, a control circuit, and a readout circuit. As detailed below, the control and / or readout circuit can be integrated in the die or provided externally, for example as laboratory measurement equipment or as another component of a module. Independent of these details, the control circuit is configured to apply a current to the first and second diode chains, for example applying the same current to both chains. The readout circuit can be configured to measure the voltage difference between the first and second diode chains, which can be the forward voltage of the different (one or more) junctions of the diode chains, see above for details.

[0031] In an embodiment, the control circuit and / or the readout circuit are integrated in a semiconductor die. This may allow for integrated temperature sensing, in particular overtemperature protection, in order to prevent, for example, overload or short circuit.

[0032] In an embodiment, the control circuit and / or the readout circuit are provided in a separate die, wherein the semiconductor die having the diode chain and the separate die are combined in a module. In this module, the die having the diode chain and the separate die may, for example, be mounted to a common board and / or be surrounded by a common housing. The dies may be electrically connected to each other via bonding wires, clips or any other connection technique. The control and readout circuits may also be distributed between the dies, for example, the control circuit is integrated in the die having the diode chain and the readout circuit is provided in the separate die and vice versa.

[0033] In an embodiment, a method of measuring temperature using a semiconductor die (in particular, using a semiconductor system) may include:

[0034] - Applying a current (in particular, the same current) to a first diode chain and a second diode chain;

[0035] - Measuring the voltage difference between the diode chains.

[0036] To apply the current, a first current source may be provided to the first diode chain and a second current source may be provided to the second diode chain, each diode chain having its own current source. Alternatively, a common current source may be provided, for example, having a multiplexer that switches repeatedly between the first and second diode chains. The diode chains may be at a common reference potential, and the obtained voltage values may be subtracted from each other to obtain V diff .

[0037] In an embodiment, a method of manufacturing a semiconductor die may include forming a first and a second diode chain. In particular, forming the first and second diode chains may include:

[0038] - Providing a polysilicon layer doped with a first doping type;

[0039] - Providing a structured mask on the doped polysilicon layer,

[0040] - Injecting a second doping type through the openings defined by the mask. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Hereinafter, the die and other embodiments are discussed in more detail by means of exemplary embodiments. Among them, the individual features can also be relevant in different combinations.

[0042] Figure 1 A die having an active region and a diode chain is shown in a vertical top view;

[0043] Figure 2 The first and second diode chains are shown in a more detailed view;

[0044] Figure 3 A circuit diagram is shown, and a system for measuring temperature using the Figure 2 diode chains is illustrated;

[0045] Figure 4 Possible devices arranged in the active region of the die in a vertical cross-section are illustrated Figure 1 ;

[0046] Figure 5 The first and second diode chains are shown in a design slightly different from Figure 2 ;

[0047] Figure 6 The possibility of a lateral arrangement of the diode chains in the active region is illustrated;

[0048] Figure 7a , b summarize some method steps. DETAILED DESCRIPTION

[0049] Figure 1 The semiconductor die 1 is shown in a vertical top view. In the active region 1a of the die 1, the semiconductor device 200 is arranged, see Figure 4 for additional details of the possible design. In the topmost metallization layer 250, contact pads 255 that are electrically connected to the underlying device structure are placed, such as source metallization plates. Next to the contact pads, control pads 256 and temperature sensing pads 251, 252 that are connected to the control terminals of the device 200 are arranged. The first temperature sensing pad 251 is connected to the first diode chain 10, and the second temperature sensing pad 252 is connected to the second diode chain 20.

[0050] The diode chains 10, 20 are formed in a polysilicon layer below the contact pads 255 and are connected via conductor lines 261, 262 in the wiring layer 260 below the topmost metallization layer 250. In this embodiment, although the diode chains 10, 20 are arranged in the active region 1a, the contact pads 255 can remain uninterrupted. The active region 1a is surrounded by an edge termination structure 1b, which is only schematically shown here and not referred to in more detail.

[0051] Figure 2 The first diode chain 10 and the second diode chain 20 are illustrated in more detail. The first diode chain 10 includes a number n 1 of diode junctions 15, where in the illustrated embodiment n 1 = 3. The second diode chain 20 includes a number n 2of the diode junction 25, where in this example n 2 = 1. Thus, the diode chains 10, 20 differ in the respective number n 1 、n 2 of their junctions 15, 25. In the illustrated embodiment, the junctions 15, 25 are provided with the same doping concentration. Alternatively, the diode chains 10, 20 may differ in the doping concentration of at least one junction (as an alternative to different numbers n 1 、n 2 or in combination with different numbers n 1 、n 2 ).

[0052] The diode chains 10, 20 are formed in the polysilicon layer 270. In the polysilicon layer 270, the first diode chain 10 is arranged in the first semiconductor region 31, and the second diode chain 20 is arranged in the second semiconductor region 32. Although the diode chains 10, 20 differ in the respective number n 1 、n 2 of their junctions 15, 25, the first and second semiconductor regions 31, 32 have the same length L. This allows for substantially the same sheet resistance in the diode chains 10, 20, and the sheet resistances can thus cancel out. See in detail Figure 3 .

[0053] The first diode chain 10 includes a plurality of first bands 11 made of a first doping type and a plurality of second bands 12 made of a second doping type. The first and second bands 11, 12 are arranged alternately in succession. In the illustrated example, the first type is n-type and the second type is p-type. Each second junction (e.g., in this example, the np junction) is bridged by a conductive bridge 14 formed above the polysilicon layer 270. In the illustrated example, the conductive bridge 14 is formed in the wiring layer 260 of the conductor lines 261, 262.

[0054] Although there is only one diode junction 25 in this example, the second diode chain 20 includes a plurality of first bands 21 made of a first doping type and a second band 22 made of a second doping type. In addition to bridging the np junction, the metal bridge 24 of the second diode chain 20 also bridges a pn junction to provide the desired number n 2 = 1 of junctions 25.

[0055] The total length L 11 of the first bands 11 of the first diode chain 10 obtained by summing the partial lengths of each first band 11 21 is equal to the total length L 12 of the first bands 21 of the second diode chain 20. 22In addition, in this example, the first and second diode chains 10, 20 are provided with the same number of conductive bridges 14, 24, which may allow the same resistance even considering the metal-semiconductor contact resistance.

[0056] Conductor lines 261, 262 connect the diode chains to respective pads 265, 266. The pads 265, 266 are formed in the wiring layer 260 and may be connected to the temperature sensing pads 251, 252 in the topmost metallization layer via vertical interconnects not shown here. Typically, additional conductor lines can be provided to connect the diode chains at opposite ends. In the example shown, the opposite ends of the diode chains 10, 20 are connected to contact pads 255 (see Figure 1 ) via vertical interconnects not shown here. In operation, the contact pad 255 may be at ground potential.

[0057] Figure 3 The circuit diagram shows a system 300 for measuring temperature using the first and second diode chains 10, 20 as shown in Figure 2 . In this example, the first diode chain 10 includes three junctions 15, i.e., diodes, and the second diode chain 20 includes one junction 25, i.e., a diode. As discussed above, for the diode chains 10, 20, the same sheet resistances 301, 302 are adjusted so that these resistance elements will cancel out in a differential measurement. This also applies to the resistance 303 of the conductor line 261 and the resistance 304 of the conductor line 262.

[0058] Via the control circuit 310, the diode chains 10, 20 can be biased with current, where the same current is applied to both diode chains 10, 20. In the example shown, the control circuit 310 includes two current sources 311, 312. Alternatively, a single current source with a multiplexer can be used. The system 300 also includes a readout circuit 320 (e.g., voltmeter 321) to measure the voltage difference between the two chains 10, 20 or branches. The voltage drop can be calculated as

[0059] V diff =V D1 +2*V D2 +I f *(R S1 +R S2 +R M +R ext )-V D1 -I f *(R S1 +R S2 +R M +R ext ) = 2*V D2 Equation 3.

[0060] Since the sheet resistances 301, 302 and the resistances 303, 304 of the conductor lines are equal and cancel each other out, the voltage difference is calculated as

[0061] V diff = 2 * V D = 2 * V f,0 - 2 * k T (T - T 0 ) Equation 4.

[0062] At the opposite ends of the diode chains 10, 20, the diode chains 10, 20 are connected to the ground domain 309 via the contact pads 255. In this example, the device 200 is connected as a low-side switch, with its first load terminal 201 (source region, see below) connected to ground and its second load contact 205 (drain region, see below) connected to the load. The control terminal 207 is connected to the control pad 256.

[0063] Figure 4 A possible device 200 is illustrated in a vertical cross-section. In this example, the device 200 is a transistor, the first load terminal 201 is the source region 202, and the second load terminal 205 is the drain region 206. In the vertical device shown, the source region 202 and the drain region 206 are arranged on opposite sides 210.1, 210.2 of the semiconductor body 210, with the body region 203 and the drift region 204 placed in the middle in the vertical direction. The source region 202, the drift region 204, and the drain region 206 are made of a first doping type, the drift region 204 has a lower concentration compared to the drain region 206, and the body region 203 is made of a second doping type. In the example shown, the first type is n-type and the second type is p-type.

[0064] In the case of a transistor device, the control terminal 207 can be the gate electrode 208. In the illustrated embodiment, it is arranged in the gate trench 215 etched into the semiconductor body 210 from the first side 210.1. Via the gate dielectric 209, the gate electrode 208 is capacitively coupled to the body region 203. Optionally, a field electrode 218 can be provided, which is capacitively coupled to the drift region 204. In the example shown, the field electrode 218 is provided below the gate electrode 208 in the same gate trench 215.

[0065] The contact structure 220 placed on the first side 210.1 of the semiconductor body 210 is connected to the first load terminal 201 (e.g., the source region 202 in this example). In addition to the contact pad 255, it also includes a vertical interconnect 256 that extends through the insulating layer 215.

[0066] As schematically indicated by the dashed lines, the polysilicon layer 270 can be integrated below the topmost metallization layer 250. In the schematic view of Figure 4 , only the topmost metallization layer 250 is shown, but additional wiring layers can be provided, for example, above the polysilicon layer 270 and below the topmost metallization layer 250. In the region of the device 200 where the respective diode chains are integrated, the vertical interconnects 265 can be interrupted (the source region 202 and the body region 203 are connected in front of or behind the plane of the drawing).

[0067] Figure 5 Another top view showing the first diode chain 10 and the second diode chain 20. As in the example of Figure 2 , the diode chains 10, 20 differ in the respective numbers n 1 , n 2 of their junctions 15, 25. However, the semiconductor regions 31, 32 are adapted to have the same length L, and the first bands 11, 21 and the second bands 12, 22 respectively have the same total length, as detailed above. Compared with the embodiment of Figure 2 , the diode chains 10, 20 of Figure 4 are not adapted to have an equal number of conductive bridges.

[0068] Figure 6 The top view of

[0069] Figure 7a again shows the complete die 1, see the above comments. In operation, the device 210 gets hot, which can result in a temperature distribution across the die 1 (or particularly, the active region 1a). Generally, it will get hotter in the center compared to the edge part, and the temperature profile has, for example, a bell shape. In order to measure as large a value or even the maximum value of the temperature as possible, the diode chains 10, 20 can be placed closer to the center 150 of the active region 1a compared to the respective edges 155, 152, 153, 154 of the active region 1a. In particular, the diode chains 10, 20 can be placed on a common isotherm 165 so that they are at the same temperature during operation.

[0069] Figure 7a , b summarize some method steps. The method of measuring the temperature 450 can particularly include: applying a current 455 to the diode chains and measuring the voltage difference between the diode chains. The formation 500 of the first and second diode chains can include: providing 505 a doped polysilicon layer, providing 510 a structured mask on the polysilicon layer, and implanting 515 opposite doping types through the mask.

Claims

1. A semiconductor die (1), comprising: A first diode chain (10) having a number n1 of diode junctions (15) connected in series, wherein n1 ≥ 1; A second diode chain (20) having a number n2 of diode junctions (25) connected in series, wherein n2 ≥ 1; The first diode chain (10) and the second diode chain (20) are used to bias with the same current as a temperature sensor (100), The first diode chain (10) and the second diode chain (20) differ from one another in terms of the respective number n1, n2 of their junctions (15, 25) and / or in terms of the doping concentration of at least one of the junctions (15, 25).

2. The semiconductor die (1) of claim 1, the first diode chain (10) having a first resistance R1 and the second diode chain (20) having a second resistance R2, wherein the first resistance R1 and the second resistance R2 are substantially equal in magnitude.

3. The semiconductor die (1) of claim 1 or 2, the first diode chain (10) being formed in a first semiconductor region (31) and the second diode chain (20) being formed in a second semiconductor region (32), wherein the first diode chain (10) and the second diode chain (20) differ in the respective number n1, n2 of their junctions (15, 25), however the first semiconductor region (31) and the second semiconductor region (32) have the same length L.

4. The semiconductor die (1) as claimed in any one of the preceding claims, the first diode chain (10) having a plurality of first strips (11) and the second diode chain (20) having at least one first strip (21), the first strips (11, 21) each being made of a first doping type, wherein the number of first strips (11, 21) in the first diode chain (10) and in the second diode chain (20) is different, but the total length L of the plurality of first strips (11) of the first diode chain (10) is 11 is equal to the total length L of the at least one first strip (21) of the second diode chain (20) 21 .

5. The semiconductor die (1) as claimed in any one of the preceding claims, the first diode chain (10) having a plurality of second strips (12) and the second diode chain (20) having at least one second strip (22), the second strips (12, 22) being respectively made of a second doping type, wherein the number of second strips (12, 22) in the first diode chain (10) and the second diode chain (20) is different, but the total length L of the plurality of second strips (12) of the first diode chain (10) is 12 is equal to the total length L of the at least one second strip (22) of the second diode chain (20) 22 .

6. A semiconductor die (1) as claimed in any one of the preceding claims, the first diode chain (10) and the second diode chain (20) differing in the respective number n1, n2 of their junctions (15, 25), wherein the first diode chain (10) and the second diode chain (20) however have the same number of conductive bridges (14, 24), in particular metal bridges, between first strips (11, 21) made of a first doping type and second strips (12, 22) made of a second doping type.

7. A semiconductor die (1) as claimed in any one of the preceding claims, comprising: A semiconductor device (200); The semiconductor device (200) comprises a load terminal (201) on a first side (210.1) of a semiconductor body (210) and a contact structure (220) on the first side (210.1) of the semiconductor body (210), in particular, the contact structure (220) is located on an insulating layer (215) arranged on the first side (210.1) of the semiconductor body (210); The first diode chain (10) and the second diode chain (20) are arranged on the first side (210.1) of the semiconductor body (210).

8. The semiconductor die (1) of claim 7, wherein the first diode chain (10) and the second diode chain (20) are each formed in a polysilicon layer arranged at the first side (210.1) of the semiconductor body (210).

9. The semiconductor die (1) of claim 7 or 8, wherein the semiconductor device (200) is arranged in an active area (1a) of the semiconductor die (1), and the first diode chain (10) and the second diode chain (20) are also arranged in the active area (1a).

10. The semiconductor die (1) of claim 9, wherein, with reference to a center (150) of the active area (1a), the first diode chain (10) and the second diode chain (20) are arranged closer to the center (150) than to an edge (151-154) of the active area (1a).

11. The semiconductor die (1) of claim 9 or 10, wherein the first diode chain (10) and the second diode chain (20) are arranged on a common isotherm (165) with reference to a temperature profile (160) of the semiconductor device (200).

12. A semiconductor die (1) as claimed in any one of claims 7 to 11, wherein the contact structure (220) comprises a contact pad in an uppermost metallization layer, wherein the first diode chain (10) and the second diode chain (20) are connected via a conductor line in a wiring layer below the uppermost metallization layer, the conductor line being in particular covered by the contact pad.

13. A system (300) for measuring a temperature value in a semiconductor die (1), comprising: A semiconductor die (1) as claimed in any one of the preceding claims; A control circuit (310) for applying a current to the first diode chain (10) and the second diode chain (20); A readout circuit (320) is used to measure a voltage difference between the first diode chain (10) and the second diode chain (20).

14. The system (300) of claim 13, wherein at least one of the control circuit (310) or the readout circuit (320) is integrated in the semiconductor die (1).

15. The system (300) of claim 13 or 14, wherein at least one of the control circuit (310) or the readout circuit (320) is provided in a separate die, the semiconductor die (1) and the separate die being combined in a module.

16. A method of measuring (450) temperature using a semiconductor die (1) as claimed in any one of claims 1 to 12 or using a system (300) as claimed in any one of claims 13 to 15, comprising the steps of: - applying (455) a current to the first diode chain (10) and the second diode chain (20); - measuring (460) a voltage difference between the first diode chain (10) and the second diode chain (20).

17. A method for manufacturing a semiconductor die (1) as claimed in any one of claims 1 to 12, comprising the steps of: - forming (500) said first diode chain (10) and said second diode chain (20).

18. The method of claim 17, wherein forming the first diode chain (10) and the second diode chain (20) comprises: - providing (505) a polysilicon layer doped with a first doping type; - providing (510) a structured mask on the doped polysilicon layer, - implanting (515) said second doping type through the openings defined by said mask.

Images