Component with Buried Doped Areas and Procedures for the Production of A Component
20220271196 · 2022-08-25
Inventors
Cpc classification
H01L2933/0091
ELECTRICITY
H01L33/08
ELECTRICITY
H01L33/025
ELECTRICITY
H01L33/24
ELECTRICITY
H01L33/14
ELECTRICITY
International classification
H01L33/14
ELECTRICITY
H01L33/00
ELECTRICITY
H01L33/08
ELECTRICITY
H01L33/24
ELECTRICITY
Abstract
In an embodiment, a component includes a carrier and a main body disposed on the carrier, wherein the main body includes a first semiconductor layer of a first charge carrier type, a second semiconductor layer of a second charge carrier type, and an optically active zone located therebetween, the optically active zone configured to emit radiation, wherein the first semiconductor layer includes a contiguous main layer and local regions at least locally buried in the main layer and laterally enclosed by the main layer, wherein the local regions are doped, and wherein the local regions has a smaller vertical layer thickness compared to the first semiconductor layer.
Claims
1.-18. (canceled)
19. A component comprising: a carrier; and a main body disposed on the carrier, wherein the main body comprises a first semiconductor layer of a first charge carrier type, a second semiconductor layer of a second charge carrier type, and an optically active zone located therebetween, the optically active zone configured to emit radiation, wherein the first semiconductor layer comprises a contiguous main layer and local regions at least locally buried in the main layer and laterally enclosed by the main layer, wherein the local regions are doped, and wherein the local regions has a smaller vertical layer thickness compared to the first semiconductor layer.
20. The component according to claim 19, wherein the local regions are individual laterally spaced regions of the first semiconductor layer, and wherein the main layer is disposed in a vertical direction at least partially between the active zone and the local regions.
21. The component according to claim 19, wherein the local regions and the main layer are based on the same semiconductor material, the main layer having a greater maximum vertical layer thickness than the local regions.
22. The component according to claim 19, wherein the main layer has a first doping concentration and the local regions have a doping concentration differing by at least 5% from the first doping concentration.
23. The component according to claim 19, wherein the first semiconductor layer is n-type, wherein the main layer has a maximum dopant concentration between 4.Math.10.sup.18 cm.sup.−3 and 4.Math.10.sup.19 cm.sup.−3 inclusive, wherein the local regions are implemented in places as current distribution bridges having a lower electrical resistance than the main layer, and wherein a doping concentration of the current distribution bridges is at least 5% greater than a doping concentration of the main layer.
24. The component according to claim 19, wherein the first semiconductor layer is n-type, wherein the main layer has a maximum dopant concentration between 4.Math.10.sup.18 cm.sup.−3 and 4.Math.10.sup.19 cm.sup.−3 inclusive, wherein the local regions are implemented in places as optically favored windows having a greater transmittance than the main layer for the radiation, and wherein the optically favored windows have a doping concentration which is at least 5% smaller than a doping concentration of the main layer.
25. The component according to claim 19, wherein the first semiconductor layer is p-type, wherein the main layer has a maximum doping concentration of between 1.Math.10.sup.17 cm.sup.−3 and 3.Math.10.sup.18 cm.sup.−3 inclusive, wherein the local regions are implemented in places as current distribution bridges having a lower electrical resistance than the main layer, and wherein a doping concentration of the current distribution bridges is at least 5% greater than a doping concentration of the main layer.
26. The component according to claim 19, wherein the first semiconductor layer is p-type, wherein the main layer has a maximum doping concentration of between 1.Math.10.sup.17 cm.sup.−3 and 3.Math.10.sup.18 cm.sup.−3 inclusive, wherein the local regions are implemented in places as optically favored windows which have a greater transmittance than the main layer for the radiation, and wherein the optically favored windows have a doping concentration which is at least 5% smaller than the doping concentration of the main layer.
27. The component according to claim 19, wherein the local regions are formed in places as current distribution bridges and in places as optically favored windows, the current distribution bridges having a higher doping concentration than the optically favored windows.
28. The component according to claim 19, wherein the second semiconductor layer comprises a contiguous main layer and local regions, wherein the local regions are buried at least in places in the main layer of the second semiconductor layer and are laterally enclosed by the main layer of the second semiconductor layer, wherein the local regions are doped, and wherein the local regions have a smaller vertical layer thickness compared to the second semiconductor layer.
29. The component according to claim 19, wherein the component has a plurality of laterally spaced through-vias, wherein the through-vias extend throughout the second semiconductor layer and the active zone into the first semiconductor layer in order to provide electrically contacting for the first semiconductor layer, and wherein, in top view of the carrier, at least some of the through-vias overlap with the local regions formed as current distribution bridges.
30. The component according to claim 19, wherein the component has a plurality of laterally spaced through-vias, wherein the through-vias extend throughout the second semiconductor layer and the active zone into the first semiconductor layer in order to provide electrically contacting for the first semiconductor layer, and wherein, in top view of the carrier, the through-vias and the local regions formed as optically favored windows are free of overlaps.
31. The component according to claim 19, wherein the component comprises a contact point for externally electrically contacting the component, wherein the local regions are formed in areas as current distribution bridges, and the current distribution bridges have a gradient with respect to their doping concentration so that the current distribution bridges having a first lateral distance from the contact point have a higher doping concentration than the current distribution bridges having a second lateral distance from the contact point, and wherein the first distance is smaller than the second distance.
32. The component according to claim 19, wherein the optically active zone has an internal vertical step in the main body, and wherein each of the first semiconductor layer and the second semiconductor layer has a corresponding vertical jump at the step of the active zone.
33. The component according to claim 19, further comprising out-coupling structures configured to increase an out-coupling efficiency of the radiation, and wherein the out-coupling structures are located in places on the main body and/or within the main body.
34. A light source comprising: the component according to claim 19, wherein the optically active zone is configured to generate the radiation in a visible, an infrared or an ultraviolet spectral range.
35. A method for producing a component having a main body comprising a first semiconductor layer of a first carrier type, a second semiconductor layer of a second carrier type, and an optically active zone located therebetween, the method comprising: forming a plurality of laterally spaced and doped regions from a semiconductor material on a growth substrate; and overgrowing the doped regions with semiconductor materials to form the main body in such that the doped regions are formed as integral subregions of the first semiconductor layer, wherein the first semiconductor layer comprises a contiguous main layer, wherein the doped regions are at least locally buried in the main layer and laterally enclosed by the main layer, wherein the doped regions adjust local electrical and local optical properties of the first semiconductor layer, and wherein the local regions have a smaller vertical layer thickness compared to the first semiconductor layer.
36. The method according to claim 35, further comprising forming a plurality of laterally spaced through-vias, the through-vias for electrically contacting the first semiconductor layer in such that the through-vias extend throughout the second semiconductor layer and the active zone into the first semiconductor layer, and the through-vias are formed in an aligned manner with respect to local buried doped regions.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Further embodiments and further developments of the component or the method will be apparent from the embodiments explained below in connection with
[0047]
[0048]
[0049]
[0050]
[0051]
[0052]
[0053]
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0054] Identical, equivalent or equivalently acting elements are indicated with the same reference numerals in the figures. The figures are schematic illustrations and thus not necessarily true to scale. Comparatively small elements and particularly layer thicknesses can rather be illustrated exaggeratedly large for the purpose of better clarification.
[0055] Referring to
[0056] The main body 2 comprises a first semiconductor layer 21, a second semiconductor layer 22 and an optically active zone 23 arranged between the first semiconductor layer 21 and the second semiconductor layer 22. In operation of the component 10, the active zone 23 is particularly configured for generating or detecting electromagnetic radiation. Preferably, the first semiconductor layer 21 is n-type. In this case, the second semiconductor layer 22 is p-type. However, it is also possible that the first semiconductor layer 21 is p-type and the first semiconductor layer 22 is n-type.
[0057] For electrically contacting the main body 2 or the component 10, the component 10 has a plurality of through-vias 20. The through-vias 20 extend along the vertical direction, in particular throughout the second semiconductor layer 22 and the optically active zone 23 into the first semiconductor layer 21. The through-via 20 is enclosed in lateral directions by an insulating structure 20I. The insulating structure 20I prevents direct electrical contact between the through-via 20 and the second semiconductor layer 22, and between the through-via 20 and the optically active zone 23. The insulating structure 20I extends along the vertical direction analogously to the through-via 20 throughout the second semiconductor layer 22 and the optically active zone 23 into the first semiconductor layer 21. In particular, the through-via 20 is in direct electrical contact with the first semiconductor layer 21. For electrically contacting the second semiconductor layer 22, the component 10 may have an electrical contact point on the second semiconductor layer 22 which is not shown in
[0058] The exemplary embodiment of a component 10 shown in
[0059] The through-vias 20, for instance all of the through-vias 20, may be electrically connected to each other via the first connection layer 60. For example, the first connection layer 60 may be externally electrically contactable via the contact layer 61. The first contact layer 61 may be arranged laterally to the connection layer 60 and have the form of a contact surface or a contact pad, or—as schematically shown in
[0060] For electrically contacting the second semiconductor layer 22, the component 10 comprises a second connection layer 50 arranged in the vertical direction between the second semiconductor layer 22 and the first connection layer 60. Referring to
[0061] The second connection layer 50 is electrically insulated from the first connection layer 60 and from the through-vias 20 by the insulating structure 20I, which is disposed regionally between the first connection layer 60 and the second connection layer 50. It is possible that the second connection layer 50 is directly adjacent to the second semiconductor layer 22. For external electrical contacting of the second connection layer 50, the component 10 comprises a second contact layer 62. The second contact layer 62 may be arranged laterally to the semiconductor body 2 and may, in particular, have the form of a contact surface or a contact pad.
[0062] As a further difference from the component 10 shown in
[0063] In
[0064] As shown schematically in
[0065] The exemplary embodiment shown in
[0066] In particular, the local doped region 3 is at least partially buried in the main layer 21B. The doped region 3 has a vertical layer thickness 3D that is smaller than a vertical layer thickness 21D of the main layer 21B or a vertical layer thickness 21D of the entire first semiconductor layer 21. For example, a ratio of the vertical layer thickness 21D to the vertical layer thickness 3D is between 1 and 10 inclusive, or between 1 and 5 inclusive, or between 1 and 3 inclusive. The vertical layer thickness 21D may be at least 1.5 times, twice, three times, or at least five times as large as the vertical layer thickness 3D. In a top view of the carrier 1, a surface facing the active zone 23 as well as all side surfaces of the doped region 3 may be covered, in particular completely covered, by the main layer 21B. It is possible that a surface of the doped region 3 facing away from the active zone 23 is free from being covered by the main layer 21B. At this surface, the doped region 3 may be flush with the main layer 21B. In particular, the first semiconductor layer 21 has a plurality of such local doped regions 3.
[0067] In
[0068] For electrical contacting of the second semiconductor layer 22, the component 10 has, for example, further connection layers 5 and 50 or at least one contact layer 62, a second connection layer 50 being in particular in direct electrical contact with the second semiconductor layer 22. The second connection layer 50 or the contact layer 62 may be formed as a mirror layer. For electrically insulating the through-via 20 from the active zone 23, the second semiconductor layer 22 and from the connection layers 5 and 50 as well as from the contact layer 62, the component 10 comprises an insulating structure 20I and/or a passivation layer 20P. The insulating structure 20I may be a single layer or a multilayer. The connection layer 20A of the through-via 20 may be completely surrounded by the insulating structure 20I in lateral directions.
[0069] The insulating structure 20I may cover, in particular completely cover, a side surface of the main body 2. At the side surface of the main body 2, the insulating structure 20I forms in particular a diffusion barrier preventing possible leakage currents via the chip edge during chip processing as well as during operation of the component 10.
[0070] In particular, the local higher-doped region 3H is formed as a current distribution bridge. In
[0071] The exemplary embodiment shown in
[0072] In top view, the higher-doped regions 3H, in particular implemented as current distribution bridges, may cover a subregion of the surface of the first semiconductor layer 21 for instance between 3% and 40% inclusive, between 3% and 30% inclusive, between 3% and 20% inclusive, or between 3% and 10% inclusive.
[0073]
[0074] The exemplary embodiment illustrated in
[0075] In top view, the lower-doped regions 3N may cover a subregion of the surface area of the first semiconductor layer 21 for instance between 20% and 90% inclusive, between 30% and 80% inclusive, between 40% and 70% inclusive, or between 30% and 60% inclusive.
[0076] In
[0077] The exemplary embodiment illustrated in
[0078]
[0079]
[0080] By using the local doped regions 3, which are implemented in particular as current distribution bridges 3H or as optically favored windows 3N within the first semiconductor layer 21, a uniform current density distribution or a uniform luminance distribution can be achieved, which is schematically shown, for example, on the right side in
[0081] In
[0082]
[0083] Referring to
[0084] Regions on the growth substrate 1A may be patterned photo-lithographically to form the doped regions 3. For example, a mask may be formed, in particular formed of a photostructurable material. Epitaxial semiconductor layers are grown in the patterned regions to form the laterally spaced and doped regions 3. Alternatively, it is possible that the semiconductor layers are epitaxially grown over a large area before these layers are patterned into the laterally spaced regions 3. It is also possible that the regions 3 are patterned during epitaxy. If the patterning is performed after epitaxy, the regions 3 may be defined locally at room temperature, which may compensate for expansion effects with respect to temperature change. The local exposure of the photostructurable mask can also be performed at room temperature.
[0085] Depending on the doping concentration, the doped regions 3 have predetermined optical properties and predetermined electrical properties. For example, a refractive index of the doped regions 3 can be set based on the doping concentration. In order to reduce the electrical resistance, the regions 3 may be high-doped. In order to improve the optical properties, in particular with respect to the transmission of light of a certain wavelength, the regions 3 may be formed with a low doping concentration.
[0086] After the formation of the regions 3, the photo-lithographic mask can be removed. The growth substrate 1A may be exposed in some areas. Referring to
[0087] In particular, the subsequent method step is carried out in an aligned manner with respect to the preceding epitaxial structures, namely with respect to the doped regions 3 buried in the main body composite 2V. The main body composite 2V may comprise adjustment marks which, for example, mark the positions of the doped regions 3 or of the main bodies 2 of the to be produced components 10.
[0088] According to
[0089] Moreover, due to the presence of the higher-doped regions 3H, the current distribution around the through-vias 20 can be improved, in particular to avoid so-called current crowding effects. Moreover, the spatial separation of the optically optimized regions 3N from the optically absorbing and current injecting regions 3H allows the realization of a first semiconductor layer 21 with spatially variable refractive index. In other words, variation from the locally defined refractive index is possible. It is also possible that color centers for wavelength conversion can be selectively generated by arranging the doped regions 3. For example, color centers are selectively embedded in predetermined locations of the main body 2, which are arranged in particular aligned with the doped regions 3. Local embedding of geometric structures can also be carried out in an aligned manner with respect to the doped regions 3.
[0090] In the finished component, a correlation between the doped regions 3 and the geometry of the component 3 can be demonstrated. Correlated variations in the doping profile or electrical conductivity in the layered regions can also be detected. In particular, the spatial arrangement of the optical properties with respect to the chip structure is detectable. In operation of the component, the current paths are in particular geometrically definable.
[0091] In a subsequent method step, an auxiliary carrier may be fixed on the main body composite 2V so that the main body composite 2V is arranged in the vertical direction between the growth substrate 1A and the auxiliary carrier. The growth substrate 1A may be subsequently removed. In particular, the subcarrier serves as a carrier 1 of the main body composite 2V or the component 10.
[0092] According to
[0093]
[0094]
[0095] As shown schematically in
[0096]
[0097]
[0098] The invention is not restricted to the exemplary embodiments by the description of the invention made with reference to the exemplary embodiments. The invention rather comprises any novel feature and any combination of features, including in particular any combination of features in the claims, even if this feature or this combination is not itself explicitly indicated in the patent claims or exemplary embodiments.