III-V semiconductor pixel X-ray detector

Description

[0001] The invention relates to a III-V semiconductor pixel X-ray detector.

[0002] A method and device for fabricating a GaAs detector for X-ray detection and image recording are known from "A Method for Adjusting the Performance of Epitaxial GaAs X-ray Detectors", Sun, GC and Bourgoin, JC, Nucl. Instrum. Methods Phys. Res., Sect. A, 2003, vol. 512, pp. 355-360, from "GaAs Schottky versus p / i / n Diodes for Pixellated X-ray Detectors", Bourgoin, JC and Sun, GC, Nucl. Instrum. Methods Phys. Res., Sect. A, 2002, vol. 487, pp. 47-49, and also from DE 602 21 638 T2. Furthermore, another GaAs image recording device for detecting X-rays is known from WO 2004 816 04 A2.

[0003] As pixels of an X-ray detector, pin structures made of GaAs are known from "GaAs Pixel-Detector Technology for X-ray Medical Imaging", Lezhneva et al.,a Russlan Microelectronics, Vol, 34, No. 4, 2005, pp. 229-241, where both epitaxially grown and implanted p+ contact regions are disclosed.

[0004] A GaAs-based X-ray detector based on Schottky diodes is known from "GaAs X-Ray System Detectors for Medical Applications", Rizzi et al., https: / / www.researchgate.net / publication / 237780321 and from US 2016 / 307 956 A1.

[0005] Further X-ray detectors are known from Dvoryankln, V, F, et al.: "Multielement X-ray row detector on GaAs with spatial resolution of 108@mm", Nuclear Instruments & Methods in Physics Research, Section A, Elsesvier BV*North-Holland, NL, Vol. 531, No. 1-2, September 21, 2004, pages 87-88, and US 2015 / 37 20 47 A1.

[0006] The X-ray detector described by Dvoryankin et al. comprises an absorption region of a first conductivity type with a top and a bottom, and semiconductor contact regions of a second conductivity type arranged along the top of the absorption region. Furthermore, the semiconductor contact regions and the absorption region comprise GaAs.

[0007] A disadvantage of the described structures are the residual or leakage currents that occur during reverse bias operation, particularly across the edges of the planar pn junctions or mesa structures.

[0008] The X-ray detector from US 2015 / 37 20 47 A1 has an absorption region of a first conductivity type with a top side and a bottom side, and at least nine semiconductor contact regions of a second conductivity type and with a first energy band gap arranged in a matrix along the top side of the absorption region, wherein a metallic front-side connection contact is arranged below the bottom side of the absorption region and a metallic rear-side connection contact is arranged above each semiconductor contact region. Furthermore, the semiconductor contact regions and the absorption region comprise or consist of GaAs. The X-ray detector also has a semiconductor passivation layer of the first or second conductivity type.

[0009] A disadvantage of the described structures are the residual or leakage currents that occur during reverse bias operation, particularly across the edges of the planar pn junctions or mesa structures.

[0010] Against this background, the object of the invention is to provide a device that further develops the state of the art.

[0011] The object is achieved by a III-V semiconductor pixel X-ray detector having the features of patent claim 1 or patent claim 2. Advantageous embodiments of the invention are the subject of subclaims.

[0012] According to the subject invention, a III-V semiconductor pixel X-ray detector is provided.

[0013] In a first alternative embodiment, the III-V semiconductor pixel X-ray detector comprises an absorption region of a first conductivity type having a top side and a bottom side, and at least nine semiconductor contact regions of a second conductivity type and having a first energy band gap arranged in a matrix along the top side of the absorption region.

[0014] In addition, the III-V semiconductor pixel X-ray detector comprises a metallic front-side terminal contact arranged below the bottom of the absorption region and a metallic back-side terminal contact arranged above each semiconductor contact region.

[0015] Furthermore, the X-ray detector has a semiconductor passivation layer of the first or second conductivity type lattice-matched to the absorption region and with an energy band gap different from the first energy band gap of the semiconductor contact regions.

[0016] The semiconductor passivation layer is arranged regionally on the top side of the absorption region and has a minimum distance of at least 2 µm or of at least 10 µm or of at least 20 µm or of at least 40 µm from each highly doped semiconductor contact region along the top side of the absorption region.

[0017] A second alternative embodiment differs from the first embodiment in that the absorption region has the first conductivity type or the second conductivity type and the III-V semiconductor pixel X-ray detector additionally has a semiconductor contact layer of the first conductivity type arranged below the bottom side of the absorption region and above the metallic front-side terminal contact.

[0018] The semiconductor contact layer preferably has a dopant concentration of at least 1•10 17< cm -3< and a layer thickness of 0.5 µm - 150 µm or of 0.5 µm - 50 µm or of 0.5 µm - 10 µm or of 0.5 µm - 5 µm.

[0019] Preferably, the minimum distance of the semiconductor passivation layer to each highly doped semiconductor contact region is not more than one layer thickness of the absorption region.

[0020] It is understood that the X-ray detector is designed to detect X-rays striking the underside in particular.

[0021] The absorption region and the semiconductor passivation layer, as well as the semiconductor contact layer if present, are preferably epitaxially generated. The layers are preferably grown sequentially on a growth substrate.

[0022] A suitable growth substrate is, for example, a GaAs substrate or a Ge substrate, e.g., with an InGaAs layer containing approximately 1 percent In to compensate for a lattice constant difference between germanium and gallium arsenide. In another embodiment, the growth substrate comprises a substrate layer and a buffer layer.

[0023] The buffer layer serves to compensate for the difference between the lattice constants of the substrate and the active epitaxial layers. For example, to grow GaAs layers on a Ge substrate, an InGaAs buffer layer with a gradually or continuously changing In content is used.

[0024] The growth substrate, e.g. the GaAs substrate or the Ge substrate and / or a buffer layer, is then removed by grinding and / or etching and / or other processes, e.g. stripping, preferably completely or, if necessary, only partially.

[0025] For example, in a first etching step, the Ge substrate is removed, with the buffer layer serving as an etch stop layer, and then by means of a further etching process, e.g. wet chemical etching, the buffer layer is removed from the photonic GaAs component.

[0026] Alternatively, the growth substrate, or the growth substrate and buffer layer, are removed using a combined grinding and subsequent etching process. This allows the majority of the material removal to be accomplished by grinding.

[0027] In a further embodiment, an additional etch stop layer is inserted below the absorption region or, if present, below the semiconductor contact layer during a manufacturing process of the stacked III-V semiconductor device.

[0028] The etch stop layer is formed, for example, between the absorption region and a buffer layer or a substrate layer or between the semiconductor contact layer and a buffer layer or a substrate layer or between a buffer layer and a substrate layer.

[0029] The etch stop layer enables a very controlled removal of the substrate layer and / or the buffer layer or only the substrate layer by means of an etching process, e.g. wet chemical etching.

[0030] In particular, the etch stop layer allows for the substrate and / or buffer layer to be removed in a highly controlled manner, if necessary, without any mechanical grinding process. Alternatively, the majority of the substrate is removed by grinding, and the remaining residue is removed by wet-chemical etching down to the etch stop layer.

[0031] The etch stop layer itself can also be removed afterwards. The etch stop layer exhibits strong chemical anisotropy compared to the adjacent layers, meaning the etch rate for the etch stop layer and the subsequent layer differs by at least a factor of 10.

[0032] The etch stop layer is typically made of GaInP or AlGaAs, and the surrounding layers are made of GaAs or GaInAs. The removed layers are no longer present in the final device.

[0033] As an alternative to the complete removal of the growth substrate, the growth substrate, e.g. a GaAs substrate doped with the second conductivity type, is only partially removed so that a remaining thin layer forms a highly doped semiconductor contact layer.

[0034] In a first alternative embodiment, the semiconductor contact regions are formed as trough-shaped regions projecting into the absorption region and are produced, for example, by an implantation.

[0035] In another alternative embodiment, the semiconductor contact regions are each formed as a mesa structure. The mesa structures are preferably arranged above the top side of the absorption region and are produced, for example, by means of at least one mask process and by means of etching and deposition processes.

[0036] In a further development, the mesa structures are arranged on the absorption area.

[0037] In a further development, the mesa structures are each formed on an intermediate layer, wherein the respective intermediate layers space the respective semiconductor contact regions from the common absorption region.

[0038] According to the invention, the semiconductor contact regions, the absorption region and, if present, the semiconductor contact layer comprise or consist of GaAs.

[0039] In a further embodiment, the X-ray detector has additional semiconductor layers made of other semiconductor materials or additional layers made of other non-semiconductor materials, e.g. a nitride layer and / or an oxide layer and / or an oxynitride layer and / or a polyimide layer as a further passivation layer.

[0040] It should be noted that the term "consists of" refers to a compound of the aforementioned materials without any other III-V elements, but includes dopants such as zinc, silicon, tin, or carbon, as well as any impurities and defects. Consequently, for example, "consists of GaAs" means that the III-V elements used are exclusively gallium and arsenic, but not In, Al, or P, etc.

[0041] The term "comprising" accordingly means that GaAs is included and other III-V elements, such as phosphorus, aluminum or indium, may be included in addition to any dopants and / or impurities and / or defects.

[0042] In a first alternative embodiment, the metallic connection contacts consist of one or more metal layers, e.g. layers comprising Au and / or Ag and / or Pb and / or Ge.

[0043] In embodiments, the metallic front-side connection contact is formed in a planar or finger-shaped or point-shaped manner, wherein it is noted that a planar front-side connection contact, for example one covering the underside of the absorption region in a layered manner, has the smallest possible layer thickness, in particular a layer thickness of 5 nm - 2 µm or of 10 nm - 1 µm, in order to keep the absorption of X-rays low.

[0044] In another embodiment, the front-side connection contact is integrally connected to the underside of the absorption region or, if present, integrally connected to the underside of the semiconductor contact layer.

[0045] Alternatively, the front-side connection contact is integrally connected to a further semiconductor layer arranged between the front-side connection contact and the absorption region.

[0046] The further semiconductor layer is, for example, a highly doped semiconductor contact layer with layer thicknesses between 1 µm and 50 µm or between 1 µm and 20 µm.

[0047] It should be noted that the matrix-like X-ray detector preferably has a circular or quadrangular, in particular rectangular or square, circumference, wherein singulation is preferably carried out by sawing.

[0048] It is further understood that the first conductivity type is n and the second conductivity type is p or that the first conductivity type is p and the second conductivity type is n.

[0049] The III-V semiconductor pixel X-ray detector is thus designed as an n-on-p or p-on-n structure.

[0050] The minimum distance of the semiconductor passivation layer, together with the semiconductor passivation layer itself, serves to suppress leakage currents.

[0051] Due to the existing distance between the passivation layer and the semiconductor contact region, only particularly low reverse currents of less than 1 µA occur, even at high reverse voltages above 400 V. In particular, the reverse currents are in a range between 0.5 nA and 50 nA or below 100 nA.

[0052] Preferably, the minimum distance to the semiconductor contact layers is at least 50% or at least 75% of the layer thickness of the absorption region.

[0053] Advantages of the semiconductor detector structure according to the invention include a particularly low reverse current and a high breakdown voltage. In particular, the breakdown characteristic curve exhibits a nearly ideal shape. The particularly low reverse current enables the application of high reverse voltages, thereby achieving very high sensitivity.

[0054] Investigations have shown that the breakdown voltage is also determined by the minimum distance between the semiconductor passivation layer and the semiconductor contact regions. With the X-ray detector according to the invention, breakdown field strengths of up to 40 V / µm and, very reliably, breakdown field strengths of over 30 V / µm can be achieved.

[0055] III-V materials, especially GaAs, also enable particularly sensitive and efficient detection of X-rays, especially low-energy X-rays, due to their high charge carrier mobility.

[0056] An advantage of the X-ray detector according to the invention is therefore its high sensitivity, which makes it possible to reduce the necessary dose to which, for example, a patient must be exposed.

[0057] Likewise, due to the high mobility of the charge carriers, only a very short time is required per image acquisition, resulting in low radiation exposure. Furthermore, the high charge carrier mobility enables color X-rays based on photon counting.

[0058] The component according to the invention can also be manufactured in relatively few process steps and thus relatively inexpensively or at least at reasonable costs.

[0059] In a further embodiment, an intermediate layer of the second conductivity type is formed between the absorption region and each semiconductor contact region, wherein the semiconductor passivation layer has the minimum distance to each intermediate layer along the top side of the absorption region.

[0060] If the semiconductor contact layer is present below the absorption region, in another development an intermediate layer of the first conductivity type is formed between the absorption region and the semiconductor contact layer.

[0061] The intermediate layers each preferably have a lower dopant concentration than the adjacent semiconductor contact region, i.e. the semiconductor contact region or the semiconductor layer.

[0062] In addition, the intermediate layers are preferably produced in the same way as the semiconductor contact region or the semiconductor contact layer, for example by implantation or as a mesa structure by deposition and etching processes or as an epitaxial layer.

[0063] It is understood that the intermediate layers are not mutually exclusive. The III-V semiconductor pixel X-ray detector can comprise one of the two intermediate layers or both.

[0064] In another embodiment, the absorption region has a dopant concentration of 8•10 11< - 1•10 14< cm -3< , i.e. a low doping, and / or a layer thickness of 80 µm - 2000 µm or of 500 µm - 2000 µm or of 900 µm - 2000 µm.

[0065] With the particularly deep absorption region for absorption and the particularly high blocking voltage due to the spaced semiconductor passivation layer, the semiconductor structure according to the invention is particularly suitable for radiation detection.

[0066] The semiconductor contact regions each preferably have a dopant concentration of at least 5•10 18< cm -3<, i.e. they are highly doped.

[0067] In a further development, the minimum distance is at least 50 µm or at least 100 µm or at least 1000 µm.

[0068] In another embodiment, the semiconductor contact regions each have a center-to-center distance of at least 20 µm or at least 50 µm.

[0069] It is understood that the spacing of the semiconductor contact regions determines the pixel pitch. Preferably, the spacing is adapted to an evaluation unit, in particular to enable connection to a corresponding evaluation unit using flip-chip technology.

[0070] In a further embodiment, the semiconductor passivation layer has a layer thickness of 0.1 µm - 1 µm. Furthermore, the semiconductor passivation layer comprises a compound of InGaP and / or AlGaAs and / or InGaAsP or consists of AlGaAs or InGaP or InGaAsP.

[0071] In another embodiment, the semiconductor passivation layer completely encloses the semiconductor contact regions or at least some of the semiconductor contact regions in a projection perpendicular to the top side of the absorption region.

[0072] In a further development, the semiconductor contact regions and the absorption region each comprise GaAs or consist of GaAs.

[0073] The invention is explained in more detail below with reference to the drawings. Similar parts are labeled with identical designations.

[0074] The embodiments shown are highly schematic, ie the distances and the lateral and vertical extensions are not to scale and, unless otherwise stated, do not have any derivable geometric relationships to each other. Figure 1 shows a cross section of a first embodiment of a III-V semiconductor pixel X-ray detector, Figure 2 shows a cross section of a second embodiment of the III-V semiconductor pixel X-ray detector, Figure 3 shows a plan view of a further embodiment of the III-V semiconductor pixel X-ray detector, Figure 4 shows a plan view of a further embodiment of the III-V semiconductor pixel X-ray detector, Figure 5 shows a cross section of a further embodiment of a III-V semiconductor pixel of the X-ray detector, Figure 6 shows a cross section of a further embodiment of the III-V semiconductor pixel X-ray detector, Figure 7 shows a cross section of a further embodiment of the III-V semiconductor pixel X-ray detector.

[0075] The illustration of the Figure 1 shows a cross section of a first embodiment of a III-V semiconductor pixel X-ray detector according to the invention for detecting X-rays R.

[0076] The X-ray detector has a matrix of four by four III-V semiconductor pixels. It should be noted that in one embodiment not shown, the matrix has three by three III-V semiconductor pixels. It should be understood that in another embodiment not shown, the X-ray detector has more than sixteen III-V semiconductor pixels.

[0077] The semiconductor pixels comprise a common absorption region ABS with a bottom side, a top side and a layer thickness D1 as well as a common front side connection contact KV, wherein the front side connection contact is formed as a metal layer with the smallest possible layer thickness D2 and covers the bottom side of the absorption region ABS and is materially connected to the bottom side of the absorption region ABS.

[0078] Each semiconductor pixel also comprises a semiconductor contact region HK, wherein the semiconductor contact regions HK each extend from a top surface in a trough-like manner to a depth T1 into the absorption region ABS. Adjacent semiconductor contact regions HK have a center-to-center spacing P1, wherein the spacing P1 corresponds to the pixel pitch.

[0079] Between the semiconductor contact regions HK, a semiconductor passivation layer HP with a layer thickness D3 is arranged on the upper side of the absorption region ABS, wherein the semiconductor passivation layer HP is materially connected to the upper side of the absorption region ABS and has a minimum distance A1 of at least 2 µm to each of the semiconductor contact regions.

[0080] An upper side of the semiconductor passivation layer HP as well as a partial region of the upper side of the absorption region ABS lying between the semiconductor passivation layer HP and the semiconductor contact regions HK and an edge region of the semiconductor contact regions HK adjacent to the upper side of the absorption region are optionally covered by a further passivation layer P, e.g. a thin silicon nitride or oxide layer (shown in dashed lines).

[0081] On the top side of each semiconductor contact region HK, a rear-side connection contact KR is arranged, wherein each rear-side connection contact KR also extends over an adjacent region of the further passivation layer P if the further passivation layer P is present and is materially connected to the respective top side of the semiconductor contact region HK and, if applicable, the further passivation layer P.

[0082] In the illustration of the Figure 2Another embodiment is shown. In the following, only the differences to the illustration of the Figure 1 explained.

[0083] The semiconductor contact regions HK are each arranged as a mesa structure on a respective partial region of the upper side of the absorption region ABS, wherein the rear-side connection contacts KR are each formed flat on an upper side of the respective mesa structure.

[0084] The X-ray detector does not have an additional passivation layer P. The common rear connection contact RK is point-shaped or formed only on a small portion of the underside of the absorption region ABS.

[0085] In the illustration of the Figure 3 a plan view of another embodiment of the X-ray detector is shown.

[0086] The X-ray detector has three times three III-V semiconductor pixels, each pixel having a semiconductor contact region HK formed as a mesa structure with an octagonal circumference and an upper side covered by the respective rear side connection contact KR.

[0087] The semiconductor passivation layer HP completely encloses each semiconductor contact region HK at the minimum distance A1, so that a partial area of ​​the upper side of the absorption region is exposed around each semiconductor contact region HK.

[0088] In the illustration of the Figure 3 A plan view of another embodiment is shown. In the following, only the differences to the illustration of the Figure 3 explained.

[0089] The semiconductor contact regions HK are each formed by implantation in a trough-shaped configuration with a circular top surface in the common absorption region ABS. The rear-side connection contacts RK also have a circular periphery.

[0090] The semiconductor passivation layer HP has a square recess in the area of ​​each semiconductor contact region HK, wherein the edge of the recess always has at least the minimum distance A1 from the respective semiconductor contact region.

[0091] In the illustration of the Figure 5 Another embodiment of a section of a III-V semiconductor pixel X-ray detector is shown. In the following, only the differences to the illustration of the Figure 1 explained.

[0092] The III-V semiconductor pixel X-ray detector has an intermediate layer ZW between each semiconductor contact region HK and the common absorption region ABS, wherein the intermediate layer has a conductivity type matching the semiconductor contact regions and a dopant concentration lower than the dopant concentration of the semiconductor contact regions.

[0093] The semiconductor passivation layer HP has the minimum distance A1 to the intermediate layer ZW along the top side of the absorption region.

[0094] The rear-side connection contacts KR are each formed on a portion of the top surface of the respective semiconductor contact region HK. The X-ray detector does not have an additional passivation layer P.

[0095] In the illustrations of the Figures 6 In each case, a further embodiment of a section of a III-V semiconductor pixel X-ray detector is shown. In the following, only the differences to the illustration of the Figure 1 or the illustration of the Figure 2 explained.

[0096] The III-V semiconductor pixel X-ray detector has a highly doped semiconductor contact layer HKS of the first conductivity type between the absorption region ABS and the front-side connection contact KV, wherein an upper side of the semiconductor contact layer HKS is integrally connected to the underside of the absorption region ABS and a lower side is integrally connected to the front-side connection contact KV.

[0097] Optionally (shown in dashed lines in each case), an intermediate layer ZW of the first conductivity type is arranged between the semiconductor contact layer HKS and the absorption region, wherein the upper side of the semiconductor contact layer HKS is materially connected to the intermediate layer ZW and the intermediate layer ZW has a lower dopant concentration than the semiconductor contact layer HKS.

[0098] In the examples of the Figures 6 and 7the absorption region ABS has either the first or the second conductivity type, so that the pn junction forms either between the semiconductor contact regions HK and the absorption region or between the semiconductor contact layer HKS and the absorption region.

Claims

1. III-V semiconductor pixel X-ray detector, comprising - an absorption region (ABS) of a first conductivity type with an upper side and a lower side, - at least nine semiconductor contact regions (HK), which are arranged in a matrix along the upper side of the adsorption region (ABS), of a second conductivity type and with a first energy band gap, wherein - a metallic front side terminal contact (KV) is arranged below the lower side of the absorption region (ABS) and - a respective metallic rear side terminal contact (KR) is arranged above each semiconductor contact region (HK), - the semiconductor contact regions (HK) and the absorption region (ABS) comprise GaAs or consist of GaAs, - the X-ray detector comprises a semiconductor passivation layer (HP) of the first or second conductivity type, characterised in that - the X-ray detector has a second energy band gap different from the first energy band gap, wherein - the semiconductor passivation layer (HP) and the absorption region (ABS) are adapted in lattice to one another, - the semiconductor passivation layer (HP) is arranged regionally on the upper side of the absorption region (ABS) and - the semiconductor passivation layer (HP) has from each semiconductor contact region (HK) along the upper side of the absorption region (ABS) a minimum spacing (A1) of at least 2 µm or of at least 10 µm or of at least 20 µm or of at least 40 µm.

2. III-V semiconductor pixel X-ray detector, comprising - an absorption region (ABS) of a first or a second conductivity type with an upper side and a lower side, - at least nine semiconductor contact regions (HK), which are arranged in a matrix along the upper side of the adsorption region (ABS), of the second conductivity type and with a first energy band gap, - a semiconductor contact layer (HKS) of the first conductivity type, wherein - the semiconductor contact layer (HKS) is arranged below the lower side of the absorption region (ABS), - a metallic front side terminal contact (KV) is arranged below a lower side of the absorption region (ABS) and - a respective metallic rear side terminal contact (KR) is arranged above each semiconductor contact region (HK), - the semiconductor contact region (HK) comprises GaAs or consists of GaAs, - the X-ray detector comprises a semiconductor passivation layer (HP) of the first or second conductivity type and has a second energy band gap differing from the first energy band gap, wherein - the semiconductor passivation layer (HP) and the absorption region (ABS) are adapted in lattice to one another, - the semiconductor passivation layer (HP) is arranged regionally on the upper side of the absorption region (ABS) and - the semiconductor passivation layer (HP) has from each semiconductor contact region (HK) along the upper side of the absorption region (ABS) a minimum spacing (A1) of at least 2 µm or of at least 10 µm or of at least 20 µm or of at least 40 µm.

3. III-V semiconductor pixel X-ray detector according to claim 2, characterised in that the semiconductor contact layer (HKS) has a dopant concentration of at least 1•1017 cm-3 and a layer thickness of 0.5 µm - 150 µm or of 0.5 µm - 50 µm or of 0.5 µm - 10 µm or of 0.5 µm - 5 µm.

4. III-V semiconductor pixel X-ray detector according to claim 2 or 3, characterised in that an intermediate layer (ZWS) of the first conductivity type is formed between the absorption region (ABS) and the semiconductor contact layer (HKS).

5. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that a respective intermediate layer (ZW) of the second conductivity type is formed between the absorption region (ABS) and each semiconductor contact region (HK), wherein the semiconductor passivation layer (HP) has the minimum spacing (A1) from each intermediate layer (ZW) along the upper side of the absorption region (ABS).

6. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the absorption region (ABS) has a dopant concentration of 8•1011 - 1•1014 cm-3 and / or a layer thickness of 80 µm - 2000 µm or of 500 µm - 2000 µm or of 900 µm - 2000 µm.

7. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the semiconductor contact regions (HK) each have a dopant concentration of at least 5•1018 cm-3.

8. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the semiconductor contact regions (HK) each extend by trough-shape into the absorption region (ABS).

9. III-V semiconductor pixel X-ray detector according to any one of claims 1 to 7, characterised in that the semiconductor contact regions (HK) are each arranged as a mesa structure above the upper side of the absorption region (ABS).

10. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the minimum spacing (A1) is at least 50 µm or at least 100 µm or at least 1000 µm.

11. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the semiconductor contact regions (HK) respectively have a centre-to-centre spacing of at least 20 µm or of at least 50 µm.

12. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the semiconductor passivation layer (HP) has a layer thickness (D3) of 0.1 µm - 1 µm.

13. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the semiconductor passivation layer (HP) comprises InGaP and / or AlGaAs and / or InGaAsP or consists of IGaP or AlGaAS or InGaAsP.

14. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that the semiconductor passivation layer (HP) in a projection perpendicular to the upper side of the absorption region (ABS) respectively fully encloses the semiconductor contact regions (HK) or at least one of the semiconductor contact regions (HK).

15. III-V semiconductor pixel X-ray detector according to any one of the preceding claims, characterised in that insofar as present the semiconductor contact layer (HKS) respectively comprises GaAs or consists of GaAs.