Light detection element, heterojunction element, and semiconductor element

Abstract

The utility model provides a light detection element, a heterojunction element and a semiconductor element. The light detection element includes a semiconductor substrate including a semiconductor material. The absorption region is located in the semiconductor substrate. The absorption region includes an epitaxial material different from the semiconductor material. The multiplication region is located in the semiconductor substrate and is separated from the absorption region. The channel region is located between the multiplication region and the absorption region, wherein the channel region and the multiplication region are in contact at a p-n junction. The enhanced channel region is doped to a first doping type opposite to the second doping type of the absorption region, so that a p-n junction is formed at the heterojunction, which increases the rate of electron transport through the heterojunction by "channeling" electrons through the heterojunction interface. Thus, the heterojunction interface is enhanced, thereby increasing the electron transport rate at the interface.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of light detection components, heterojunction components and semiconductor components, especially a kind of light detection components, heterojunction components and semiconductor components with enhanced channel structure (enhanced channel structure). BACKGROUND

[0002] An image sensor is a solid-state device configured to convert incident light (e.g., photons) into an electrical signal. The electrical signal is then provided to a processor that can convert the electrical signal into data that can be stored and / or viewed by a user. Integrated chips (ICs) are used with image sensors for a wide range of modern electronic devices, such as cell phones, security cameras, medical devices, etc. SUMMARY

[0003] According to some embodiments of the utility model, the light detection component includes a semiconductor substrate, an absorption region, a multiplication region, and a channel region. The semiconductor substrate includes a semiconductor material. The absorption region is located within the semiconductor substrate, and the absorption region includes an epitaxial material that is different from the semiconductor material. The multiplication region is located within the semiconductor substrate and is separate from the absorption region. The channel region is located between the multiplication region and the absorption region, and the channel region and the multiplication region meet at a p-n junction.

[0004] According to some embodiments of the utility model, the heterojunction component includes a substrate, an epitaxial material, a first doped region, a second doped region, a third doped region, and a surface region. The epitaxial material is located between sidewalls of the substrate. The first doped region is disposed in the substrate to be adjacent to the epitaxial material. The second doped region is disposed in the substrate to be adjacent to the first doped region and to abut the first doped region at a first p-n junction. The third doped region is located between the epitaxial material and the first doped region, and the third doped region abuts the first doped region at a second p-n junction. The surface region extends from the third doped region and along a perimeter of the epitaxial material, and the surface region includes a same doping type as the first doped region.

[0005] According to some embodiments of the utility model, the semiconductor component includes a substrate, an absorption region, a first doped region, a channel region, and a multiplication region. The absorption region is located within the substrate. The first doped region is located within the substrate and is laterally separated from the absorption region, and the first doped region laterally surrounds the absorption region. The channel region is located within the substrate, and the channel region is located on an outer sidewall of the absorption region and laterally surrounds the absorption region. The multiplication region includes the first doped region and extends between the first doped region and the channel region.

[0006] Based on the above, since the enhanced channel region is doped to a first doping type opposite to a second doping type of the absorption region, a p-n junction is formed at the heterojunction, which increases the electron transport rate through the heterojunction interface by "funneling" the electrons through the heterojunction interface. Thus, the heterojunction interface is enhanced, thereby increasing the electron transport rate at the interface.

[0007] In order to make the above features and advantages of the present application more apparent, the following embodiments are described in detail, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 Cross-sectional views of photodetector elements having a heterojunction between semiconductor materials are illustrated for some embodiments.

[0009] Figure 2 Cross-sectional views of photodetector elements are illustrated for some additional embodiments.

[0010] Figure 3 Top views of photodetector elements are illustrated for some embodiments, corresponding to a line A-A' in Figure 2

[0011] Figure 4 Cross-sectional views of photodetector elements having a base portion of a surface region that is counter-doped and adjacent to a channel region are illustrated for some embodiments.

[0012] Figure 5 Cross-sectional views of first and second photodetector elements arranged side-by-side and separated by an isolation structure are illustrated for some embodiments.

[0013] Figures 6-7 Cross-sectional and top views of photodetector elements having a channel region at a heterojunction interface are illustrated for some alternative embodiments.

[0014] Figures 8-9 Cross-sectional and top views of photodetector elements having a channel region at a heterojunction interface are illustrated for some alternative embodiments.

[0015] Figure 10 Cross-sectional views of photodetector elements having a channel region at a heterojunction interface are illustrated for some alternative embodiments.

[0016] REFERENCE NUMERALS:

[0017] ​100, 400, 600, 1000, 800: photodetector device;

[0018] 102: semiconductor substrate;

[0019] 102a: first photodetector device;

[0020] 102b: second photodetector device;

[0021] 102l: lower surface;

[0022] 102u: upper surface;

[0023] 102u1: first upper surface;

[0024] 102u2: second upper surface;

[0025] 104, 602: channel region;

[0026] 106, 604: first doped region;

[0027] 108, 608: second doped region;

[0028] 110a: first p-n junction;

[0029] 110b: second p-n junction;

[0030] 110c: third p-n junction;

[0031] 112: absorption region;

[0032] 112a: first absorption region;

[0033] 112b: second absorption region;

[0034] 114: lateral connection region;

[0035] 115: multiplication region;

[0036] 116: vertical connection region;

[0037] 118: heterojunction interface;

[0038] 120, 606: surface region;

[0039] 120b: base portion;

[0040] 120s: sidewall portion;

[0041] 122: incident photon;

[0042] 124: connection region;

[0043] 126: contact structure;

[0044] 128: epitaxial cap;

[0045] 132: dielectric structure;

[0046] 134: conductive contacts;

[0047] 136: Metal lines;

[0048] 138: isolation layer;

[0049] 402: subset base portion;

[0050] 502, 1004: isolation structure;

[0051] 1002: liner;

[0052] 1006: metal contacts. DETAILED DESCRIPTION

[0053] The various aspects of the disclosure will be best understood with the aid of the following detailed description read in light of the accompanying drawings. It should be noted that the various features are not necessarily drawn to scale in the attached figures. In fact, the dimensions of the various features can be arbitrarily increased or decreased for the sake of clarity. It should be noted that, for the sake of clarity, not all features of a particular implementation are necessarily described or depicted. In the description below, numerous specific details are discussed to provide a thorough understanding of various implementations. However, implementations can be practiced without some or all of these specific details. In other instances, well known operation mechanisms have not been described in particular detail so as not to unnecessarily obscure the disclosure.

[0054] The following detailed description is provided to enable one of ordinary skill in the art to best utilize the disclosure. The following detailed description includes specific details for the purpose of providing a thorough understanding of the various implementations. However, it will be apparent to those skilled in the art that the disclosure can be practiced without these specific details. In some instances, well-known structures have not been described in detail in order to avoid obscuring aspects of the disclosure.

[0055] A photodetector element is a semiconductor element designed to convert energy from a radiation source (e.g., light, infrared radiation, X-ray, etc.) into an electrical current. Photons or energy from the radiation source are generated on an absorption region of the photodetector element and are absorbed by the semiconductor material of the absorption region. The absorption generates electron-hole pairs that are separated by an electric field of the photodetector element to generate a current (e.g., photocurrent) across a p-n junction within the photodetector element, where the current is proportional to the intensity of the incident radiation source.

[0056] Certain photodetector elements, such as avalanche, single photon avalanche, PN, PIN photodetector elements or the like, utilize different semiconductor materials within the photodetector element structure. For example, germanium (Ge) can be used in the absorption region, while silicon (Si) is used as the bandgap material and base substrate, facilitating an electronic channel from the Ge absorption region through the doped region, electrical wires, and contacts to other circuit components. These elements are heterojunction elements because they have an interface between two different semiconductor types or materials that have different band structures (e.g., Ge-Si interface). In addition, heterojunction elements can include a p-n junction between the doped absorption region and the doped region of the base substrate, separated by an intrinsic region. That is, the interface of the heterojunction can be between the doped region of the epitaxial material and the intrinsic region of the semiconductor material. While heterojunction elements provide advantages such as enhanced carrier mobility, high speed performance, and low power consumption, they can also exhibit adverse characteristics such as dark current leakage due to high defect density at the heterojunction interface. The defect density at the heterojunction interface (Ge-Si interface) can be attributed to lattice mismatch, band offset, and interface states between materials of different crystal structures that have different bandgaps. As a result, heterojunction elements can suffer from low electron transport rates due to defects at the heterojunction impeding electron transport.

[0057] In some embodiments, the present disclosure relates to a heterojunction element having a photodetector element with an absorption region of epitaxial material (e.g., Ge semiconductor material) surrounded by a semiconductor substrate (e.g., Si semiconductor material) that facilitates an electronic channel from the absorption region through the doped region, electrical wires, and contacts to other circuit components. The heterojunction element has an enhanced pass region (hereinafter "pass region") at the heterojunction between the doped region of the base substrate and the epitaxial material. The pass region is doped to a first doping type opposite a second doping type of the absorption region, thus forming a p-n junction at the heterojunction that increases the electron transport rate through the heterojunction interface by "funneling" electrons through the heterojunction interface. As a result, the heterojunction interface is enhanced, thus increasing the electron transport rate at the interface.

[0058] Figure 1A cross-sectional view of a photodetector element 100 having a channel region doped and interfacing with an absorption region is illustrated for some embodiments. In some embodiments, the photodetector element 100 is an avalanche photodetector or a single-photon avalanche diode.

[0059] The photodetector element 100 includes a semiconductor substrate 102 composed of a semiconductor material. An absorption region 112 is disposed within the semiconductor substrate 102. The absorption region 112 includes an epitaxial material different from the semiconductor material. In some embodiments, the absorption region 112 has a fill factor of 1% to 99% of an area laterally spanned by the photodetector element 100 and a height of 0.1 micrometers (pm) to 3 pm. In some embodiments, the semiconductor material is silicon (Si) and the epitaxial material is germanium (Ge), although it is understood that the materials can be reversed. For example, in some embodiments, the absorption region 112 can include p-type doping. In some embodiments, the absorption region 112 is p-type doped germanium with a concentration of 1e16 (1 x 1016) atoms / cm3to 1e18 (1 x 1018) atoms / cm3. 16 ) atoms / cm3. 3 ) atoms / cm3. 18 A heterointerface 118 is located at a surface of the absorption region 112 that is adjacent to a surface of the semiconductor substrate 102. In some embodiments, the heterointerface 118 is a Ge-Si interface.

[0060] The heterointerface 118 is present at locations where an outer sidewall of the absorption region 112 interfaces with an inner sidewall of the semiconductor substrate 102 and where a lower surface of the absorption region 112 interfaces with an upper surface of a recess of the semiconductor substrate 102, respectively. In certain embodiments (e.g., in Figure 2 In some embodiments, the heterointerface 118 is composed of a Ge-Si alloy having a lattice constant between about 56.6 nanometers (nm) and about 54.3 nm. In certain cases, the heterointerface 118 can have a thickness ranging from 1 angstrom to 20 nm, from 10 angstroms to 10 nm, or other similar values. In some embodiments, the heterointerface can have a U-shaped cross-section.

[0061] A multiplication region 115 is disposed within the semiconductor substrate 102 and is separate from the absorption region 112. The multiplication region 115 includes a first doped region 106 disposed below the absorption region 112 (e.g., epitaxial material) and a second doped region 108 disposed below the first doped region 106 and adjacent to the first doped region 106 at a first pn junction 110a. In some embodiments, the first doped region 106 and the second doped region 108 have different doping types. For example, the first doped region 106 may be p-type, while the second doped region 108 may be n-type. Therefore, in some embodiments, the multiplication region 115 includes an n-type region with n-type dopant and a p-type region with p-type dopant.

[0062] Lateral connection region 114 extends laterally from the second doped region 108 beyond the outer wall of the absorption region 112, wherein lateral connection region 114 includes the same doping type as the second doped region 108. Vertical connection region 116 extends from the lateral connection region 114 and perpendicularly beyond the bottom surface of the absorption region 112. Vertical connection region 116 includes the same doping type as the lateral connection region 114. Furthermore, lateral connection region 114 and vertical connection region 116 form connection region 124. In some cases, connection region 124 is referred to as a "guard ring" because vertical connection region 116 laterally surrounds absorption region 112.

[0063] Channel region 104 is located between multiplication region 115 and absorption region 112. Channel region 104 and multiplication region 115 intersect at the second pn junction 110b. Furthermore, channel region 104 and absorption region 112 intersect at the third pn junction 110c. In some embodiments, channel region 104 is referred to as the third doped region and may include the same doping type as the second doped region 108. In some embodiments, channel region 104 includes an n-type region doped with n-type, and the p-type doping of the multiplication region is located between channel region 104 and the n-type region of the multiplication region. In some embodiments, the doping concentration of channel region 104 is 1e16 (1 × 10⁻¹⁶). 16 ) atoms / cubic centimeter to 1e18 (1×10) 18atoms per cubic centimeter. In some embodiments, the channel region 104 and the absorption region 112 have substantially the same doping concentration. The channel region 104 is located within the semiconductor substrate 102, and thus the multiplication region 115 and the channel region 104 comprise semiconductor material. As a result, the heterojunction interface 118 extends between the absorption region 112 and the channel region 104. In some embodiments, the channel region 104 has a lateral width of 0.4 micrometers (pm) to a lateral width substantially the same as the absorption region 112, and the channel region 104 can have a height from 0.1 pm to 3 pm.

[0064] In some embodiments, during operation of the photodetector element 100, a biasing circuit (not shown) biases the first p-n junction 110a above a breakdown voltage. Under this biasing condition, when an incident photon 122 (or energy, such as from a radiation source) is absorbed in the absorption region 112, an electron-hole pair is generated, and the electron passes through the channel region 104 and into the multiplication region 115, which includes the first p-n junction 110a. The electron passes through the second p-n junction 110b between the channel region 104 and the multiplication region 115, and the electron passes through the third p-n junction 110c between the channel region 104 and the absorption region 112. Thus, the channel region defines an electron path by “funneling” or facilitating the passage of the electron through the heterojunction interface 118 at the third p-n junction 110c and into the multiplication region 115. The electron is then accelerated in the multiplication region 115 to gain sufficient kinetic energy for impact ionization, generating a secondary electron-hole pair. The secondary electron and hole pair of the secondary electron-hole pair, in turn, are accelerated and impact ionized to generate more electron-hole pairs in the multiplication region 115. Further impact ionized holes and electrons thus rapidly generate a large current (e.g., an avalanche current) that can be self-sustaining if the element is biased above the breakdown voltage (e.g., avalanche breakdown). Under these conditions, an observable electronic signal is generated that can be correlated in time with the initial incident photon. After detection, the biasing circuit instantaneously reduces the bias of the photodetector element 100 below the breakdown voltage to quench the multiplication, and the photodetector element 100 can then return to its quiescent state in preparation for detecting further incident photons.

[0065] In photodetector 100, channel region 104 is formed of a doped material opposite the doping type of absorption region 112, rather than, for example, being formed of intrinsic material, to provide several advantages. For example, third p-n junction 110c increases the rate of electron transport across the heterojunction interface by "funneling" electrons through heterojunction interface 118 and to multiplication region 115 of semiconductor substrate 102. Thus, the heterojunction interface is enhanced, thereby increasing the rate of electron transport across the interface. At the same time, current leakage and dark current due to lattice mismatch and defects of heterojunction interface 118 can still be suppressed by the doped Si region surrounding absorption region 112, for example, Figure 2 surface region 120 of FIG. 1.

[0066] Figure 2 Cross-sectional views of some additional embodiments of photodetector 100 are illustrated. Figure 3 top views of some embodiments of photodetector 100 of FIG. 1 corresponding to Figure 2 line A-A' are illustrated.

[0067] Reference is now made to Figure 2 and Figure 3 , Figure 2 and Figure 3 photodetector 100 of FIG. 1 includes Figure 1 other embodiments not illustrated in FIG. 1. Photodetector 100 includes an epitaxial material disposed within semiconductor substrate 102 (e.g., within absorption region 112). First doped region 106 is disposed within semiconductor substrate 102 below the epitaxial material. Second doped region 108 is disposed within semiconductor substrate 102 below first doped region 106 and adjacent to first doped region 106 at first p-n junction 110a. Third doped region (e.g., channel region 104) is disposed between the epitaxial material and first doped region 106. Third doped region is adjacent to first doped region 106 at second p-n junction 110b and is adjacent to the epitaxial material at third p-n junction 110c. Thus, first doped region 106 is disposed above second doped region 108, third doped region is disposed above first doped region, and the epitaxial material is disposed above third doped region. In some embodiments, first doped region 106 extends beyond outer edges of third doped region.

[0068] The surface region 120 encircles the bottom and sidewalls of the absorption region 112, extending to the upper surface 102u of the semiconductor substrate 102. The surface region 120 includes a doped portion of the semiconductor substrate 102. In some embodiments, the surface region 120 includes the same doping type as the absorption region and has a similar doping concentration. The surface region 120 includes a base portion 120b having a central opening corresponding to the channel region 104 and includes a sidewall portion 120s extending upward along the outer sidewalls of the absorption region 112. In some embodiments, the base portion 120b and the sidewall portion 120s have different thicknesses, e.g., the base portion 120b is thinner than the sidewall portion 120s. A multiplication region 115 is disposed within the semiconductor substrate 102, separate from the absorption region 112. The multiplication region 115 includes a first doped region 106 disposed below the absorption region 112 and a second doped region 108 disposed below and adjacent to the first doped region 106 at the first p-n junction 110a. Thus, the channel region 104 extends from the multiplication region 115 and through the surface region 120 to be adjacent to the absorption region 112 at the heterojunction interface 118.

[0069] In some embodiments, the thickness of the channel region 104 is greater than the thickness of the base portion 120b of the surface region 120. In some embodiments, the width of the channel region 104 is less than the width of the first doped region 106. Thus, the base portion 120b of the surface region 120 is separated from the first doped region 106 of the multiplication region 115 by the semiconductor substrate 102. Further, the channel region 104 is adjacent to the multiplication region 115, the semiconductor substrate 102, and the surface region 120. The surface region 120 establishes a partial U-shaped cross-sectional profile extending from the channel region 104 and generally surrounding the absorption region 112. Figure 2 ) from a top view Figure 3 ), the surface region 120 is annular, where the surface region 120 laterally surrounds the absorption region 112. In some embodiments, the surface region 120 extends laterally beyond the epitaxial material and vertically along the outer edge of the epitaxial material to the upper surface of the substrate.

[0070] The surface region 120 includes a semiconductor material and has the same doping type as the absorption region 112. In some embodiments, for example, the absorption region 112 is p-type and the surface region 120 is p-type. In other examples, the absorption region 112 is Ge-doped p-type and the surface region 120 is Si-doped p-type. Because the absorption region 112 and the surface region 120 include different bandgap materials, the absorption region 112 and the surface region 120 are adjacent at the heterojunction interface 118. The surface region 120 surrounding the absorption region 112 can reduce leakage current, thus potentially mitigating dark current due to stress, dislocations, etc. generated at the Ge-Si interface region.

[0071] In some embodiments, the contact structure 126 extends from the vertical connection region 116 to a top surface of the semiconductor substrate 102. The contact structure 126 may, for example, include the same semiconductor material and the same doping type as the vertical connection region 116. In some embodiments, the contact structure 126 has a higher doping concentration than the vertical connection region 116. Thus, the connection region 124 can include the contact structure 126, the lateral connection region 114, and the vertical connection region 116, all separated from the absorption region 112 and the surface region 120 by the semiconductor substrate 102.

[0072] The lateral connection region 114 extends laterally from the second doped region 108 beyond an outer sidewall of the first doped region 106 and an outer sidewall of the absorption region 112. The vertical connection region 116 extends vertically from the lateral connection region 114 beyond the channel region 104 and a bottom surface of the absorption region 112. In some cases, the connection region 124 can be referred to as “ring-shaped” because, when viewed from above (e.g., in a top view), the vertical connection region 116 laterally surrounds the absorption region 112. Figure 3 In some embodiments, the second doped region 108 and the connection region 124 collectively form a U-shaped cross-sectional profile, when viewed in a cross-sectional view (e.g., in a cross-sectional view taken along the plane of the page), that generally surrounds the first doped region 106, the channel region 104, and the absorption region 112. Figure 2 In some embodiments, an isolation layer 138 is disposed in the semiconductor substrate 102 and beneath the connection region 124. The isolation layer 138 can include a semiconductor material of the semiconductor substrate 102 and can be doped (e.g., p-type).

[0073] A dielectric structure 132 extends to the upper surface 102u of the semiconductor substrate 102. The dielectric structure 132 may be or includes silicon dioxide or a low-k dielectric material. An epitaxial cap 128 is disposed within the dielectric structure 132, wherein the epitaxial cap 128 extends from the upper surface of the absorption region 112. The epitaxial cap 128 extends beyond the outer sidewall of the absorption region 112 and covers the top surface of the sidewall portion 120s of the surface region 120. Conductive contacts 134, such as metal contacts, extend through the dielectric structure 132. The conductive contacts 134 are connected to contact structures 126, and one of the conductive contacts 134 passes through the epitaxial cap 128 to connect to the absorption region 112. A metal wire 136 is connected to the conductive contacts 134 and is operatively connected to a bias circuit (not shown), which may include semiconductor elements formed on the semiconductor substrate 102 or on another semiconductor substrate. For example, if the semiconductor element is formed on the semiconductor substrate 102, the semiconductor element may include a transistor comprising fins and / or gate electrodes disposed on the upper surface 102u of the semiconductor substrate 102, or may include a transistor comprising fins and / or gate electrodes disposed on the lower surface 102l of the semiconductor substrate 102. In this case, vias may pass through the semiconductor substrate 102 to facilitate operational connections.

[0074] Figure 4 Cross-sectional views of additional embodiments of the photodetector 400 are shown, in which the substrate portion 120b of the surface region 120 is reverse-doped. That is, the surface region 120 is first doped with a first type of dopant, and then subsequently doped with a second type of dopant, which is different from the first type.

[0075] like Figure 4 The light detection element 100 shown is characterized by... Figure 2Similar, but with a different implementation of the surface region 120b of the base portion 120b. The doping type of the base portion 120b is the same as the sidewall portion 120s of the surface region 120. The sub-base portion 402 of the base portion 120b is different from the doping concentration of the sidewall portion 120s. The sub-base portion 402 is disposed on the outer sidewall of the channel region 104 and is adjacent to the absorption region 112. The sub-base portion 402 is formed according to a reverse doping process. The sub-base portion 402 is first formed with a first doping type according to a first doping process, and then formed with a second doping type according to a second doping process, where the first and second doping types are different. For example, in some embodiments, the sub-base portion 402 is formed with n-type doping (e.g., the first doping type) in the first doping process, then a shield is placed on the channel region 104, and the sub-base portion 402 is formed with p-type doping (e.g., the second doping type) in the second doping process along with the base portion 120b. The second doping process counteracts the effect of the first doping process and makes the sub-base portion 402 into the second doping type according to a reverse doping process. This process has the advantage of minimizing the processing steps to form the channel region 104 and the surface region 120.

[0076] Figure 5 A cross-sectional view of some embodiments is illustrated in which the first and second photodetecting elements are arranged side-by-side in the semiconductor substrate 102 and separated by an isolation structure 502. In Figure 5 , the first and second photodetecting elements 100a and 100b have features as previously described in Figure 2 , where features labeled with “a” and “b” have the same or similar structure and function as described in Figure 2 , for example, the 112a and 112b in Figure 5 correspond to the 112 in Figure 2 . Thus, in Figure 5 , the first vertical connection region 116a laterally surrounds the first absorption region 112a of the first photodetecting element 100a, and the second vertical connection region 116b laterally surrounds the second absorption region 112b of the second photodetecting element 100b. The isolation structure 502 separates the first vertical connection region 116a from the second vertical connection region 116b and defines the isolation structure 502. In some embodiments, the isolation structure 502 is intrinsic (e.g., single crystalline silicon). In other embodiments, the isolation structure 502 is a deep trench isolation structure made of a dielectric material and / or includes a doped portion of the semiconductor substrate 102 (e.g., doped p-type). It should be understood that any number of photodetecting elements can be arranged in the semiconductor substrate 102 and they can be arranged in an array, for example, including multiple rows and columns. Furthermore, while Figure 5is depicted, where the first light detecting element 102a and the second light detecting element 102b correspond to Figure 2 In other embodiments, however, the first light detecting element 102a and the second light detecting element 102b can correspond to other depicted embodiments described herein, or combinations thereof.

[0077] Figure 6 Cross-sectional views of alternative embodiments of some light detecting elements 600 having a channel region 602 at a heterojunction interface 118 are depicted. Figure 7 Cross-sectional views of alternative embodiments of some light detecting elements 600 having a channel region 602 at a heterojunction interface 118 are depicted. Figure 6 Top views of some embodiments at line A-A' of the light detecting element 600 in

[0078] Reference is now made to Figure 6 and Figure 7 The light detecting element 600 exhibits alternative features relative to the light detecting element 100 having a ring-shaped channel region 602. The absorption region 112 is disposed within the semiconductor substrate 102. A surface region 606 is disposed at an outer periphery of the absorption region 112, as shown in the cross-sectional view Figure 6 ) In some embodiments, the surface region 606 and the absorption region 112 of Figure 6 and Figure 7 correspond to the surface region 120 and the absorption region 112 of Figures 2-5 The first doped region 604 is laterally separated from the surface region 606 by the semiconductor substrate 102. The first doped region 604 is connected to the conductive contact 134 by the contact structure 126.

[0079] The channel region 602 interfaces with the absorption region 112 at the heterojunction interface 118 and is located at opposite sidewalls of the absorption region 112. The channel region 602 extends from the semiconductor substrate 102 and through the surface region 606. Thus, the channel region 602 is disposed on an outer sidewall of the absorption region 112. Furthermore, the channel region 602 is separated from the first doped region 604 by the semiconductor substrate 102. That is, the intrinsic substrate of the semiconductor substrate 102 is disposed between the channel region 602 and the first doped region 604. The channel region 602 defines a ring shape from the top view Figure 7 ) that laterally surrounds the absorption region 112. Furthermore, the surface region 606 extends from the channel region 602, where the surface region 606 is disposed on the sidewalls of the absorption region 112 and on a bottom surface of the absorption region 112.

[0080] In some embodiments, the first doped region 604 and the channel region 602 include the same doping type, for example, a first doped type. The absorption region 112 includes a second doping type different from the first doping type. For example, the first doping type may be n-type, and the second doping type may be p-type. Therefore, the channel region 602 is connected to the absorption region 112 at the pn junction of the sidewalls of the channel region 602 located at the heterojunction interface 118. Therefore, when the photodetector element 600 is biased and excited by a radiation source, a current is generated from the absorption region 112, through the channel region 602, through the semiconductor substrate 102, and to the first doped region 604. The channel region 602 facilitates the transport of electrons through the heterojunction interface 118.

[0081] Figure 8 Cross-sectional views of alternative embodiments of photodetectors 800 with heterojunction interfaces are shown. Figure 9 The diagram shows the corresponding Figure 8 A top view of some embodiments of the photodetector element 800 along line A-A'. In some embodiments, the photodetector element 800 is an avalanche photodetector or a single-photon avalanche diode.

[0082] Now for reference Figure 8 and Figure 9 The photodetector 800 is illustrated with alternative features associated with the photodetector 600, wherein a second doped region 608 is located between a channel region 602 and a first doped region 604. In some embodiments, the channel region 602 is referred to as a third doped region. The first doped region 604 and the channel region 602 include... Figures 6-7 The same doping type is discussed. The second doped region 608 includes a second doping type different from the first doping type of the channel region 602 and the first doped region 604. For example, in some embodiments, the first doping type is n-type and the second doping type is p-type. Therefore, a first pn junction is formed between the first doped region 604 and the second doped region 608, a second pn junction is formed between the second doped region 608 and the channel region 602, and a third pn junction is formed at the heterojunction interface 118 between the channel region 602 and the absorption region 112. The first doped region 604 and the second doped region 608 form the multiplication region 115 of the photodetector element 600. The multiplication region 115 laterally surrounds the channel region 602 and the absorption region 112, thereby providing a view from the top view ( Figure 9 This forms a ring-shaped multiplication zone. For example... Figure 1 and Figure 2 The channel region 602 facilitates the passage of electrons through the heterojunction interface 118 and into the multiplication region 115.

[0083] Figure 10Some embodiments are illustrated with respect to a cross-sectional view of a mesa type photodetector device 1000 having a channel region at a heterojunction interface.

[0084] The mesa type photodetector device 1000 illustrates an alternative implementation in which certain aspects of the photodetector are located between two upper surfaces of the semiconductor substrate 102. For example, one or more of the absorption region 112, the surface region 120, or the channel region 104 can extend above the first upper surface 102ul of the semiconductor substrate 102. In some implementations, the second upper surface 102u2 of the semiconductor substrate 102 extends above the absorption region 112 and the surface region 120. In some implementations, the multiplication region 115 is located below the first upper surface 102ul. An isolation structure 1004 is located within the semiconductor substrate 102, connected to the metal contact 1006, and laterally offset from the vertical connection region 116. The isolation structure 1004 isolates the photodetector from surrounding devices within the semiconductor substrate 102. A liner 1002 is located above the semiconductor substrate 102, extending along the first upper surface 102ul and the second upper surface 102u2 of the semiconductor substrate 102. In some implementations, the liner 1002 can be, for example, a dielectric liner. The metal contact 1006 contacts the surface region and the vertical connection region 116 to bias the mesa type photodetector device 1000.

[0085] In some embodiments, the disclosure relates to a photodetector. The photodetector includes a semiconductor substrate having a semiconductor material. An absorption region is disposed within the semiconductor substrate. The absorption region includes an epitaxial material different from the semiconductor material. A multiplication region is disposed within the semiconductor substrate and separated from the absorption region. In one embodiment, the multiplication region and the channel region include the semiconductor material. In one embodiment, the channel region includes an n-type region and the multiplication region includes an n-type region and a p-type region, wherein the p-type region of the multiplication region is located between the channel region and the n-type region of the multiplication region. In one embodiment, the photodetector further includes a surface region; the surface region extends around a bottom surface and sidewalls of the absorption region, and the surface region includes the semiconductor material doped with a same doping type as the absorption region. In one embodiment, the channel region extends from the multiplication region and through the surface region. In one embodiment, the channel region is contiguous to the multiplication region, the semiconductor substrate, and the surface region. In one embodiment, the photodetector further includes a connection region; the connection region includes a lateral connection region and a vertical connection region doped, wherein the connection region is separated from the absorption region by the semiconductor substrate, and the connection region extends from the multiplication region and substantially around the absorption region.

[0086] In other embodiments, the disclosure relates to a heterojunction device. The heterojunction device includes an epitaxial material between sidewalls of a substrate. A first doped region is disposed in the substrate adjacent to the epitaxial material. A second doped region is disposed in the substrate adjacent to the first doped region and abutting the first doped region at a first p-n junction. A third doped region is disposed between the epitaxial material and the first doped region, wherein the third doped region abuts the first doped region at a second p-n junction. A surface region extends from the third doped region and along a perimeter of the epitaxial material, wherein the surface region includes a same doping type as the first doped region. In an embodiment, the foregoing third doped region extends through the foregoing surface region to abut the foregoing epitaxial material. In an embodiment, the foregoing surface region extends laterally beyond the foregoing epitaxial material and vertically along an outer edge of the foregoing epitaxial material to an upper surface of the foregoing substrate. In an embodiment, the foregoing surface region extends from opposing sidewalls of the foregoing third doped region. In an embodiment, the foregoing first doped region is separated from the foregoing surface region by the foregoing third doped region. In an embodiment, the heterojunction device further includes a lateral connection region and a vertical connection region; the foregoing lateral connection region extends laterally from the foregoing second doped region and beyond outer sidewalls of the foregoing epitaxial material and the foregoing first doped region; the foregoing vertical connection region extends vertically from the foregoing lateral connection region and beyond a bottom surface of the foregoing third doped region and the foregoing epitaxial material. In an embodiment, the heterojunction device further includes a contact structure, the foregoing contact structure extending from the foregoing vertical connection region to an upper surface of the foregoing substrate. In an embodiment, the foregoing first doped region is positioned on top of the foregoing second doped region, the foregoing third doped region is positioned on top of the foregoing first doped region, and the foregoing first doped region extends beyond an outer edge of the foregoing third doped region. In an embodiment, the heterojunction device further includes an epitaxial cap, the foregoing epitaxial cap extending from an upper surface of the foregoing epitaxial material.

[0087] In other embodiments, the disclosure relates to a semiconductor device. The semiconductor device includes a substrate and an absorption region disposed within the substrate. A first doped region is disposed within the substrate and laterally separated from the absorption region. The first doped region laterally surrounds the absorption region. A channel region is disposed within the substrate. The channel region is disposed on an outer sidewall of the absorption region and laterally surrounds the absorption region. A multiplication region, which includes the first doped region, extends between the first doped region and the channel region. In one embodiment, the semiconductor device further includes a surface region; the surface region extends from the channel region, wherein the surface region is disposed along a sidewall of the absorption region and a bottom surface of the absorption region, wherein the surface region and the absorption region comprise a first doping type. In one embodiment, the semiconductor device further includes a second doped region; the second doped region is disposed within the multiplication region, wherein the second doped region extends between the channel region and the first doped region, and wherein the absorption region and the second doped region comprise the first doping type, and the first doped region and the channel region comprise a second doping type different from the first doping type. In one embodiment, the first doped region adjoins the substrate at a first p-n junction, the channel region adjoins the substrate at a second p-n junction, and the channel region adjoins the absorption region at a third p-n junction.

[0088] The foregoing summary is provided to illustrate features of various embodiments so that those skilled in the art can better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they can devise other processes and structures, which, although not expressly mentioned in the foregoing, embody the principles of the present disclosure and achieve the same results. Those skilled in the art should also appreciate that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions and alterations thereto without departing from the spirit and scope of the present disclosure.

[0089] Finally, it should be noted that the above-described embodiments are merely intended to illustrate the technical solutions of the present disclosure, but not to limit the present disclosure; although the present disclosure has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still make modifications to the technical solutions recorded in the above embodiments, or make equivalent replacements to some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A photodetector element, comprising: Including: a semiconductor substrate comprising a semiconductor material; an absorption region within the semiconductor substrate, the absorption region comprising an epitaxial material different from the semiconductor material; a multiplication region within the semiconductor substrate and separate from the absorption region; and a pass region between the multiplication region and the absorption region, wherein the pass region meets the multiplication region at a p-n junction. wherein the multiplication region and the pass region comprise the semiconductor material.

2. The photodetecting element according to claim 1, wherein wherein the pass region comprises an n-type region and the multiplication region comprises an n-type region and a p-type region, wherein the p-type region of the multiplication region is between the pass region and the n-type region of the multiplication region.

3. The photodetecting element according to claim 1, wherein Further including:

4. The photodetecting element according to claim 1, wherein a surface region extending around a bottom surface and sidewalls of the absorption region, and the surface region comprising the semiconductor material doped with a same doping type as the absorption region. Including:

5. A heterojunction device, comprising: a substrate; an epitaxial material between sidewalls of the substrate; a first doped region disposed in the substrate adjacent to the epitaxial material; a second doped region disposed in the substrate adjacent to the first doped region and abutting the first doped region at a first p-n junction; a third doped region between the epitaxial material and the first doped region, wherein the third doped region abuts the first doped region at a second p-n junction; and a surface region extending from the third doped region and along a perimeter of the epitaxial material, wherein the surface region comprises a same doping type as the first doped region. wherein the third doped region extends through the surface region to abut the epitaxial material. wherein the surface region extends laterally beyond the epitaxial material and vertically along an outer edge of the epitaxial material to an upper surface of the substrate.

6. The heterojunction element according to claim 5, wherein Including:

7. The heterojunction element according to claim 5, wherein a substrate; 8. A semiconductor element characterized by comprising: an absorption region within the substrate; a first doped region within the substrate and laterally separated from the absorption region, wherein the first doped region laterally surrounds the absorption region; a pass region within the substrate, wherein the pass region is on an outer sidewall of the absorption region and laterally surrounds the absorption region; and a multiplication region comprising the first doped region and extending between the first doped region and the pass region. Further including: a surface region extending from the pass region, wherein the surface region is disposed along a sidewall of the absorption region and a bottom surface of the absorption region, wherein the surface region and the absorption region comprise a first doping type. Further including:

9. The semiconductor device according to claim 8, wherein a second doped region within the multiplication region, wherein the second doped region extends between the pass region and the first doped region, and wherein the absorption region and the second doped region comprise a first doping type and the first doped region and the pass region comprise a second doping type different from the first doping type. ​ 10. The semiconductor device according to claim 8, wherein ​ ​

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