Trench insulation structure with enlarged electrically conductive sidewall and method for its construction

Abstract

Semiconductor device with a first active component region (20) and with a second active component region (22), wherein the first active component region (20) and the second active component region (22) extend planarly along a first lateral direction (L1) and a second lateral direction (L2) differing from it; and with a trench insulation structure (10, 10') that electrically insulates the first active component region (20) from the second active component region (22) along the first lateral direction (L1) and has at least one electrically conductive side wall (14, 14', 14"); wherein the trench insulation structure (10, 10') comprises: - a continuously insulating trench insulation base wall (30); - several spaced-apart trench insulation sections (32a, 32b) with electrically conductive side wall sections (14a, 14b) located between them;- wherein the multiple trench insulation sections (32a, 32b) and the electrically conductive sidewall sections (14a, 14b) are spaced apart from the trench insulation base wall (30) (a, b).;

Description

[0001] This disclosure (and claims) generally relates to insulation trenches in semiconductor devices with electrically conductive Side walls that have an additional function, for example to provide electrical conductivity.

[0002] Semiconductor devices are manufactured on suitable substrates, e.g. semiconductor wafers, and the like, wherein appropriate Layers and layer sequences are created, which are appropriately structured in the lateral direction so that a desired function is achieved. In this way, very complex components, such as transistors, resistors, capacitors, and the like, are formed. The corresponding functional layers are not only produced on the substrate material, e.g. by deposition, but such layers are also created Layers are also created within the substrate material itself, for example by introducing suitable dopant substances to make it electrically suitable. to create set areas.

[0003] It is often necessary to electrically isolate component areas from each other laterally and also in depth. For this purpose Isolation structures in the form of trenches are frequently used, which are also referred to as trench isolation structures in the following. The corresponding trench insulation structures are usually manufactured in such a way that a trench is first cut into the support material or Semiconductor material is produced by etching to a depth suitable for the intended purpose. For example, the Design forms or the layout of corresponding trenches are provided in such a way that a specific component area is enclosed and thus separated from others. The component areas are electrically separated, whereby one or more components may be provided in the enclosed structure and outside the enclosed structure, another component area is provided in the form of a closed area or an empty area. is maintained in which no semiconductor components are manufactured or will be manufactured.

[0004] The trenches are typically created as structures with straight sections that extend in lateral directions. They are arranged in a row to achieve the desired lateral enclosure of component areas and thus their (lateral) electrical insulation. after the trenches have been at least partially filled with suitable insulating material.

[0005] Fig. 1 schematically shows a top view or layout of a semiconductor device 99, in which first component areas 20 , in in which, for example, semiconductor components in the form of transistors 20a, resistors, or the like are provided, by one or more other active areas 22 are to be electrically isolated. This is done on the basis of trench isolation structures 9, which consist of straight lines are composed of sections that extend in the respective lateral directions, so that typically a rectangular shape or also results in the shape of a polygon when the corresponding enclosed component area 20 is enclosed in a ring shape.

[0006] In the depth direction (in the direction perpendicular to the plane of Fig. 1), the corresponding isolation trench 9 extends to a depth such as is required for the given semiconductor device 99. For example, many devices are based on a SOI architecture is produced, in which a buried insulation layer is provided, which ensures reliable electrical insulation at depth. semiconductor device. Therefore, the insulation trenches often extend up to or through this buried insulation layer. through, so that the corresponding component areas 20 represent essentially completely electrically isolated regions. They are laterally and in the depth is limited by insulating material.

[0007] In recent developments, the trench insulation structures are intended to have additional functions besides the electrical insulation of adjacent areas. For example, isolation trenches with conductive sidewalls are provided, which, depending on the application, ensure the greatest possible protection. They are intended to provide low-resistance electrical connections to deeper component layers. Examples of such applications include: Trench-insulated smart power technology in SOI architecture on silicon wafers, where the insulation trench serves as an insulation element, as as previously described, and on the other hand, it is used as an electrical connection to a buried doped area. For example A heavily n-doped side wall of an isolation trench would be a suitable connection to a buried n-doped layer, so that, on the one hand, electrical connection is possible, and on the other hand, space-consuming connection structures that require additional complex measures are avoided. Process steps would be necessary to produce the buried doped layer, which could be avoided.

[0008] In other examples, isolation trenches with highly conductive sidewall doping can also be used in pn-insulated processes, to connect, for example, doped buried layers.

[0009] Insulation grooves in SOI silicon wafers are also frequently used to separate different components in integrated smart power circuits. To isolate components, e.g. transistors, or entire areas with different potentials from each other.

[0010] Fig. 2 shows a sectional view of a schematic insulation trench structure with a dual function, i.e., with the function of electrical insulation. Isolation and simultaneous connection of buried conductive layers. As shown here, the semiconductor device 99, which is used, for example, in Fig. 1 shows a top view of a carrier material, e.g. a silicon disk 2, with a buried insulating layer 4 applied to it. For example, when considering an SOI architecture. The buried insulation layer 4 can be made of silicon dioxide, silicon nitride, for example. or similar. In the example shown, the isolation trench structure 9 is intended to potentially separate two active areas 20 and 22. to separate from each other, in which components, e.g. transistors, and the like are manufactured or are to be manufactured. The isolation trench structure 9 It features an insulating material as an insulating wall 12, for example in the form of silicon dioxide, or the like, and has electrically conductive properties. Sidewalls 14, which are formed from a doped semiconductor material.

[0011] The doped side walls 14 make it possible to create corresponding buried layers 6, 6a, which are located in the respective Component area 20 or 22 are designed to be electrically connected, so that a well-conducting connection is established across the left and right side walls. 14 to the respective buried layer 6 or 6a. Thus, an electrical connection with relatively low resistance can be established by an active Material 8 (or layers 8a, 8b) can be implemented without having to provide special vias. On the other hand, it ensures the insulation material of the isolation trench 12 ensures that the two areas 20 and 22, i.e., in particular the respective active materials 8a or 8b and the respective buried conductive layers 6a , 6b , are electrically separated from each other.

[0012] As shown, for example, in Fig. 1, the insulation trench structure 9 can be the component to be insulated or the part to be insulated Enclose the area, e.g., area 20. For example, in the form of a rectangle, or also in a ring shape if the entire isolation trench 12 is a polygon. is designed.

[0013] Such an application of isolation trenches is described, for example, in US 5,734,192 A, US 6,394,638 B1, US 9,385,190 B2. US 5 283 461 also describes a trench structure in which the building elements to be isolated are separated by a network of isolation trenches.

[0014] In order to achieve a dual use of the isolation trench, as explained with reference to Fig. 2, the side walls of the The insulation trench is doped, for example by depositing a doped layer and subjecting the component to a heating process. so that dopant atoms can diffuse from the doped layer into the trench sidewalls, thereby creating conductive sidewalls. Such a The technique is described, for example, in US 4,676,847.

[0015] Other strategies for doping the sidewalls include ion implantation at specially set angles, so that all Trench walls should be appropriately enriched with doping agents. Such techniques are described, for example, in US 5013. 673, US 5,047,359, US 6,509,240.

[0016] The resistance and thus the conductivity of the side wall with the doping is determined, among other things, by the penetration depth of the Doping into the semiconductor material of the sidewall, often a silicon material, and by the concentration of the dopant atoms, i.e., by the Integral of the concentration from the side wall of the doping container to the transition formed by the doping in the carrier material. A reduction Increasing the resistance and thus the conductivity of the side walls can therefore typically only be achieved in process engineering by increasing the Concentration of the doping and / or by introducing the dopant atoms to a greater depth in the support material.

[0017] However, there are process-related limits to both the penetration depth of the dopant atoms and the concentration of the doping, so that the reduction in resistance of the sidewall doping is limited. For example, the penetration depth is limited by the Overall process defined temperature-time budget of the subsequent process steps to be carried out for the manufacture of semiconductor components are determined so that the corresponding temperature treatment for diffusing the dopant atoms only applies according to the specified parameters. The temperature-time budget is feasible. Therefore, the temperature and / or the duration of exposure to the elevated temperature cannot determine the feasibility. Requirements for maintaining a high doping concentration and / or deep penetration doping must be selected accordingly, but it The specifications for these parameters must be considered in relation to the overall process. Depending on the dosing method, There are also limits to the concentration of doping agents introduced, since, for example, during implantation, the implantation angle and the The maximum possible implantation dose is subject to limits.

[0018] In view of the aforementioned situation, it is therefore an object of the invention to provide a greater degree of flexibility in the provision of to reach suitable conductive sidewalls, especially if at least partially electrically conductive sidewalls are located in an insulation trench to be provided for.

[0019] According to the invention, this problem is solved by a corresponding design or layout of trench isolation structures. is provided, thereby making an increased total volume available for conductive material.

[0020] The claimed semiconductor device has two active component regions that are isolated from each other. The isolation is achieved along a First direction. The component areas extend across a surface, along two directions, which are designated as lateral directions. The insulation is carried out. through a trench isolation structure (also isolation trench structure). This trench structure has at least one insulating trench isolation layer. Base wall, wherein the base wall runs continuously. Additionally, at least one electrically conductive side wall is provided. As far as walls are concerned. When spoken of, they run continuously. In addition to the existing walls, there are trench insulation sections and electrically conductive ones. Side wall sections are provided.

[0021] The composition of the aforementioned sections, which can be, for example, alternately insulating and electrically conductive, results in a heterogeneous wall that is partly insulating and partly electrically conductive.

[0022] The corresponding enlargement of the side wall and thus of the available volume of conductive material in the Trench isolation structure is achieved by providing additional isolation trench sections that serve for lateral isolation. They may or may not, but in any case, they enlarge the conventional design form and thus lead to a layout characterized by a larger side wall and thus, in practical implementation, an increase in volume leads to an increase in conductive material, e.g. from doped semiconductor material or with metal-containing material.

[0023] In a first advantageous embodiment, a semiconductor device is provided in which a trench insulation structure is a The trench isolation structure separates the first active component area from a second active area. It comprises several trench isolation sections. (or isolation trench sections) with electrically conductive side wall sections located between them, extending along the first of the lateral directions, i.e., parallel to the base wall.

[0024] The distinction between the terms lies in the sections (standalone pieces of the respective type) and the respective wall as such, they It runs continuously. The pieces also form a wall, which, however, is heterogeneous, containing both conductive and non-conductive elements – overall. conductive, and widen at least one electrically conductive side wall.

[0025] The trench isolation sections can preferably be elongated sections. They have a main direction of extension and a secondary direction of extension. Extension direction that is shorter than the main extension direction. This is preferably used to describe trench isolation sections, which are elongated or rectangular in shape. The conductive sidewalls located between them are also geometrically determined in the same way. Sections.

[0026] A preference exists if the main extension direction runs parallel to the trench isolation base wall, e.g. claim 2.

[0027] Another preference is an arrangement of the trench isolation sections with their main extension direction in the second lateral Direction, e.g. claim 3.

[0028] The electrically conductive sidewall sections located between them adapt to the geometry of the trench insulation sections. They They also lie here between the trench isolation sections, in one orientation or another.

[0029] A further advantage lies in the use of trench insulation sections whose orientation faces both directions of the exhibits the aforementioned orientations to define a kind of line or heterogeneous wall that includes insulation sections and electrically conductive It has sidewall sections. These can alternate, or there can be several trench insulation sections of one orientation, followed by... several trench isolation sections of the other orientation are arranged in a row. Each section is placed between two consecutive sections. Trench insulation sections include an electrically conductive side wall section, e.g. claim 4.

[0030] Several electrically conductive side walls can be provided, for example at least one electrically conductive side wall each on the one hand and on the other hand the continuously insulating trench insulation base wall, or on both sides of the heterogeneous wall made of electrical conductive sidewall sections and insulating trench insulation sections.

[0031] Preferably, the two lateral directions are independent of each other, i.e., they are perpendicular. one another in the manner of an XY coordinate system, which defines the area of ​​the active regions.

[0032] The previously mentioned heterogeneous wall consisting of trench insulation sections and electrically conductive side wall sections can be enclosed on both sides by a continuously electrically conductive side wall, e.g. claim 5. Each trench insulation section is thereby embedded between electrically conductive sections of the electrically conductive side wall and the electrically conductive side wall sections (in (Extension direction of the heterogeneous wall). In this way, an extended electrically conductive sidewall structure is formed, in which insulating Trench isolation sections are embedded.

[0033] Preferably, at least two continuously electrically conductive side walls are located on at least one side of the insulating base wall. provided. Additional or identical walls may be provided on both sides of the continuously insulating base wall.

[0034] This results in an increase in the outline of the trench isolation structure and thus an increase in the side wall, so that More conductive material can be provided on one or both side walls.

[0035] Compared to conventional isolation trenches, which are essentially constructed from straight pieces running in the same direction are to include corresponding areas of adjacent component regions (active areas, with or without components) that extend along this same lateral To extend in the direction of isolation, additional sections are inserted according to the invention, which are connected to a continuous base wall, which is for the actual electrical insulation ensures that they may or may not be connected.

[0036] For example, by providing individual isolation trench sections that are not connected to the insulating base wall, Overall, a large side wall with spaced insulating sections is achieved. They do not share a common contact surface with the insulating base wall.

[0037] The separate trench isolation sections therefore no longer take over the isolation of the adjacent active areas, but are They are specifically designed to provide the volume of the enlarged side wall and thus offer increased conductivity. The basic electrical insulation is achieved through the continuous base wall.

[0038] The corresponding trench isolation sections separated from the base wall can have elongated shapes, as previously described. explained, with a main and a secondary direction of extension, the main direction of extension being parallel to the first lateral are oriented in the same direction or deviating from it (e.g., claim 2, claim 3, or claim 4). The overarching direction of extension of the The trench isolation structure or the insulating base wall is assumed to be the first of the two lateral directions.

[0039] The active component area can be understood as one that is designed to accommodate at least one semiconductor component or is provided for, or already contains, e.g. claim 12.

[0040] The trench insulation structure can be connected in the depth direction of a building element designed, for example, as a SOI. In this case A conductive connection can be addressed to connect the vertical conductive or conductive sidewalls or conductive sidewall- To connect sections, as well as an insulating connection, in which the isolation trench sections are insulated at depth.

[0041] The horizontal layers in the depth of the semiconductor device can be located on one or both sides of the continuous Trench insulation base walls are provided and can support individual potentials.

[0042] The trench insulation base wall can form an insulating connection to a buried insulating layer of dielectric material. have.

[0043] Although the trench insulation base wall provides continuous insulation, it can be sectioned in the first and second lateral directions. extend. Preferably, the directions alternate and further preferably by an angle of 90° to create a meandering structure in the to obtain the plane of the two lateral extension directions, e.g. claim 13 or 23.

[0044] In a further embodiment as an independent concept, a semiconductor device is obtained which also has two active areas separated from each other. Insulated. The insulation is provided by the trench insulation structure, which has a trench insulation base wall for insulation purposes. This causes It has continuous insulation when viewed in one of the two lateral directions. It also has at least one electrically conductive side wall. provided for, e.g. claim 15.

[0045] In addition to the trench insulation base wall, several trench insulation sections with associated electrically conductive side walls are installed. The trench insulation sections are formed into segments, with the trench insulation segments being an integral part of the trench insulation base wall, i.e., they connect to it. Unlike in the previous design, they are not spaced apart from it, but rather terminate in or extend from this trench insulation base wall. directly, without any distance.

[0046] Thus, isolation is provided between the trench isolation base wall and the trench isolation sections. Nevertheless, by The trench insulation sections and their electrically conductive side wall sections increase the effective wall area, i.e., An increase in the volume of the conductive material is achieved. The trench insulation sections preferably extend into the second lateral Direction and the trench isolation base wall in the first lateral direction.

[0047] In an advantageous embodiment, the insulating trench insulation sections are functionally connected to the trench insulation base wall. be, i.e., the corresponding trench insulation sections are insulated as insulating material and connected to the insulating base wall, or even It has become part of this.

[0048] In other advantageous embodiments, the multiple trench insulation sections are formed as extensions of the insulating base wall. provided, wherein in advantageous variants (e.g. claims 17, 18) the extensions extend in the second lateral direction, i.e. e.g. transversely to the Extend the direction of extension of the base wall.

[0049] At least one continuously electrically conductive side wall is provided.

[0050] In a particular embodiment, two continuously electrically conductive side walls are provided, preferably one on each side of the Trench insulation base wall, e.g. claim 16.

[0051] The electrically conductive side wall sections can have alternating directions; they extend in both lateral directions. preferably alternating on at least one length section of the trench isolation base wall used for orientation, e.g. claim 21.

[0052] The geometric design of the electrically conductive side wall sections can be finger-shaped, can extend over a longer The area can result in a simplified meander shape, or a combination of these two geometries can extend along the length of the Form trench insulation base wall, e.g. claim 20.

[0053] In the finger-shaped design and orientation, which is also possible for the trench insulation sections, adjacent electrical Conductive sidewall sections merge together, so that with several such geometries along the global extension direction The trench isolation base wall has a comb-like formation of insulating and non-insulating sections.

[0054] The trench insulation sections can originate from the trench insulation base wall and the finger-shaped electrically conductive Side wall sections extend from the electrically conductive side wall.

[0055] In a further independent variant, the first and second active areas are located along the first lateral direction. isolated from each other. Both active areas extend in both lateral directions. This design has a special form of Trench isolation base wall. This extends or runs in both lateral directions, but is continuously insulating. Due to its geometry Even without separate trench isolation sections, directions emerge in the trench isolation base wall that point in the second lateral direction. The trench insulation base wall, shaped in this geometrically defined way, has at least one electrically conductive side wall, or its... assigned so that it also receives sections in the second lateral direction, which run in this direction, and not only in the first lateral direction, e.g. claim 23.

[0056] This allows more wall length to be placed per given unit length, and if the trench insulation base wall is electrically conductive As sections are assigned, the volume of the conductive material will also increase (per given unit of length).

[0057] By forming the trench isolation base wall, which extends section by section in the first and second lateral directions, Preferably alternating, this results in a simplified meandering shape of the trench isolation base wall.

[0058] The person skilled in the art can also imagine the arrangement in plan view as consisting of a straight section with a length which the the extent of the two areas to be isolated along the first lateral direction significantly exceeds, “is folded in such a way” that Finally, the resulting length of the folded structure corresponds to the length of the extension required to achieve the desired or necessary insulation. to obtain. The "folding" can also be done in the layout in such a way as to create a "rounded" structure, e.g. in waveform, whereby the rounding in the actual realization in the semiconductor material depends on the specifications of the used Technology depends.

[0059] Despite its simplified meandering shape, the trench insulation base wall provides continuous electrical insulation and The electrically conductive side wall, which is part of its path, remains electrically conductive throughout. This embodiment lacks [the following features]. Trench insulation sections that are provided separately, i.e., neither those that connect to the trench insulation base wall, nor those that which are located on either side of the trench isolation base wall and are therefore subject to complaint.

[0060] Due to the geometry of the trench insulation base wall and also the first electrically conductive side wall, the opposite The side of the trench insulation base wall can accommodate another electrically conductive side wall, e.g., claim 27, 28. The second electrically conductive Electrically conductive extensions may be associated with the side wall, either extending from it or entering it and forming those shapes of the Trench isolation base wall, formed from three successive sections of the (continuous) trench isolation base wall two of which run in the second lateral direction and one in the first lateral direction.

[0061] The variants of the extensions (e.g. claim 15) or the “folding” (e.g. claim 23) distribute more conductive Sidewall material per length section of the insulation trench (or trench insulation base wall). Providing more volume is directly by widening the electrically conductive side wall (e.g., claim 1). Both solutions, volume or larger (longer) wall or Wall surface area per length section of the trench insulation base wall achieves a reduction in the electrical resistance of the side wall (of all its (Sections taken together).

[0062] In advantageous embodiments, the corresponding trench insulation structures can extend up to or be buried in a Extend the insulation layer, as is the case for SOI architectures.

[0063] The electrically conductive side surfaces and side wall sections can be arranged to form one or more buried conductive layers or areas extend to provide improved conductivity due to the increased overall sidewall.

[0064] In further aspects of the disclosure, the fabrication of a semiconductor device based on a layout of a Trench insulation structure provided. The layout of the trench insulation structure is designed such that appropriate trench insulation- Sections are provided in addition to a base wall running in the direction of extension of the trench isolation structure. This allows The proportion of the available electrically conductive sidewall of the trench insulation structure is increased, thus enabling further functions of the Trench insulation structures can be implemented with increased efficiency and a higher degree of flexibility in the design of semiconductor devices. is achievable because, for example, good electrical connection of component areas and deeper conductive layers can be accomplished, without requiring additional low-resistance connection structures. Based on the corresponding layout, a Semiconductor device manufactured using suitable means, e.g. claim 30.

[0065] Further advantageous variants of the method for manufacturing the semiconductor device based on the layout are derived from the further dependent claims arise and also result from the following detailed description of the figures.

[0066] The embodiments of the invention are illustrated by means of examples and not in a manner that limits the invention. Figures can be transferred to or read into the patent claims. Identical reference numerals in the figures indicate similar elements. Fig. Figure 1 shows a top view of a conventional building element 99 with conventional trench insulation structures 9. Figure 2 shows a schematic Cross-sectional view of the component 99 with conventional insulation trench 12 with two conductive side walls 14. Fig. 3 shows schematically a top view of a new building element 100 or of a layout of a trench insulation structure 10, in which additional extended trench insulation Sections 32a together with an elongated, continuous insulating base wall 30 are provided to form the side wall. and thus to increase the achievable volume of the conductive edge of the trench isolation structure 10. Fig. 3a and Fig. 3b are sections along Q31 and Q32. Fig. 4 schematically shows a top view of another new component or layout of a trench insulation structure 10' in the supervision, whereby extended trench isolation sections 32b are additionally provided, the respective main extension direction Le transverse the extension direction of the continuously insulating base wall 30. Fig. 4a and Fig. 4b are sections along Q41 and Q42. Fig. 5 shows schematically a top view or layout of a semiconductor device 100 with a trench insulation structure 10* , in which a “simplified meandering” shape or geometry of the continuous insulating base wall 30 is shown, so that overall A larger side wall area (per length segment) is achieved. Fig. 6 shows another embodiment 10* in plan view, where insulating Trench insulation sections 30c and 30d are arranged on a trench insulation base wall 30 and form insulating extensions 30c and 30d. The extensions represent the trench isolation base wall 30. The extensions run in a direction transverse to the extension direction of the insulating base wall 30. .

[0067] With reference to the accompanying drawings, further details of the inventions will now be described.

[0068] It should be noted that in the figures, identical elements are consistently named with the same reference numerals, and elements that are labelled with References to the prior art are also used with the same reference numerals in embodiments of the inventions. A redundant description of corresponding elements has been omitted. Thus, Figures 1 and 2, in conjunction with the associated... Description of part of the revelation of the examples of the inventions of the other characters.

[0069] It should be noted that the trench isolation base wall 30 typically changes its direction of extension, for example parallel to a second lateral direction L2 runs when the area 20 and / or 22 is to be enclosed, as shown, for example, in the top view of Fig. 1 is.

[0070] Fig. 3 shows a schematic top view or layout of a first semiconductor device 100, which in illustrative embodiments The semiconductor device may have components such as those described, for example, in connection with Figures 1 and 2. e.g. a carrier disk, e.g. the carrier disk 2 , a buried insulation layer, e.g. the buried layer 4 of Fig. 2, one or more buried doped layers, e.g. layers 6, 6a of Fig. 2, an “active” semiconductor material, e.g. the active material 8, 8b of the Fig. 2 shows, for example, when the semiconductor device is to be provided in the form of an SOI architecture, as previously described.

[0071] Furthermore, a first active component area 20 and a second active area 22 are provided in the semiconductor device 100 such that that they extend section by section along a first lateral direction L1 and are separated from a trench isolation structure 10 along their extension in the first lateral direction L1 are electrically isolated.

[0072] In the illustrated embodiment, the first component area 20 contains one or more semiconductor components 20a, e.g. one or several transistors, diodes or other active elements, while the second active area 22 is an active area without semiconductor components represents. In other cases, the second active region 22 may also contain one or more active semiconductor elements or components.

[0073] The trench insulation structure 10 comprises a trench insulation base wall 30, which is in the form of an insulating material, e.g. in the form of of silicon dioxide, silicon nitride, and the like, and is designed as a continuous, elongated element, the The extension direction Le runs parallel to the first lateral direction L1. The base wall 30 has two functions: Firstly, it causes electrical isolation of the corresponding sections of the active areas 20 and 22 along the first lateral direction L1, and secondly it allows an electrical connection to deeper layers, e.g. to layers 6 (as 6a and 6b) of Fig. 2, by providing electrically conductive Side walls 14, 14' .

[0074] It should be noted again that the trench isolation base wall 30 changes its direction of extension, for example parallel to the second lateral direction L2, when the area 20 and / or 22 is to be enclosed, as shown, for example, in the top view of Fig. 1.

[0075] The preceding and following considerations each apply to a base wall 30 which extends in a single direction extends. That is, if an essentially rectangular overall structure is considered, the statements of this disclosure apply to each “Side edge” of the rectangle 9 bounded by trench isolation (from corner to corner in each case).

[0076] The trench insulation base wall 30 has a correspondingly assigned first electrically conductive section on the side of the second component area 22. Side wall 14, which in the illustrated embodiment contains a conductive material, e.g. doped semiconductor material, metal-containing material, or the like.

[0077] In one embodiment, the electrically conductive side wall 14 on the side of the component area 22 can form a conductive connection to a to create a buried layer in component area 22, which has the properties of a conventional conductive connection. The corresponding The connection to a buried conductive layer is then relatively independent of the presence of a low-resistance connection, since, for example, no functional components in the active area 22 are present. Therefore, this area of ​​the conventional structure can be considered in relation to the insulating wall 30 and the one also arranged here. Electrically conductive side wall 14 may well be suitable.

[0078] On the other hand, for example, a conductive connection can be established on the side of component area 20, e.g. to a buried Layer 6a, which in addition to the “conventional” conductive side wall 14’, is formed by an increase in the conductive material to a higher conductivity. This is achieved by providing the trench insulation sections 32a, as they have associated conductive sidewalls. Sections 14a are created in addition to the continuous conductive side wall 14' by creating sections 32a as "island-like". Trench insulation sections are provided so that, in addition to the conductive side wall 14', the trench insulation base wall 30 on one side of the active area 20 the further side wall sections 14a , each between two adjacent island-like trench isolation Sections, resulting in a significantly enlarged (thickened) overall sidewall and thus a larger volume of the associated conductive material. contribute.

[0079] Accordingly, the resistance also decreases in the vertical direction downwards into the depth, e.g. to the conductive buried layer 6a .

[0080] A further continuous conductive side wall 14" is provided at the left edge of the image.

[0081] Three parallel walls are formed on either side of the trench insulation base wall 30, two continuous conductive side walls 14' and 14" and in between a section-wise conductive wall made up of the trench insulation sections 32a and the electrically conductive side wall sections 14a . The direction of extension of this mixed wall is Le.

[0082] In the illustrated embodiment, the trench insulation sections 32a are provided as elongated elements, the The direction of extension (or orientation) runs with Le parallel to the first lateral direction L1.

[0083] Although the trench insulation sections 32a could in principle be connected to the base wall 30, as is also shown below in other As described in the design variants, the arrangement of the island-like sections 32a spaced away from the base wall 30 is particularly advantageous, since thus the entire functional side wall 14a, 14' and 14" , i.e. also the conducting area facing the insulating base wall and facing away from it, is available for the absorption of conductive material.

[0084] The increase in the volume of the conductive material of the electrically conductive side wall is evident. Functionally, the electrical The conductive side wall is described by 14 in all embodiments; in the example of Fig. 3, there is a conductive side wall 30 on both sides of the insulating base wall 30. an electrically conductive side wall 14 and 14' .

[0085] The electrically conductive side wall 14' is in turn only a section of the further electrically conductive sections adjoining this side Side wall sections 14a and the further side wall 14". The side wall sections 14a are located between themselves and at a distance a The trench isolation sections 32a are located spaced from the base wall 30, and it closes off, facing away from the insulating base wall 30. the further electrically conductive side wall 14".

[0086] The individual components 14', 14" and 14a functionally form an electrically conductive side wall with a large volume, or when it viewed from the surface of Fig. 3, with a large wall surface (viewed in horizontal section).

[0087] The two sections in Fig. 3a and Fig. 3b show the two vertical section planes Q31 and Q32 of Fig. 3. The difference between these The sections shown indicate the presence of a trench insulation section 32a in Fig. 3a and the absence of such section 32a when the conducting Side wall section 14a is shown in cross-section. The electrically conductive, buried layer 6a (left) is visible in both figures. right active area 22 the buried conductive layer 6 .

[0088] The distance a shown in Fig. 3, which is between the trench insulation base wall 30 and the trench insulation sections, should be mentioned. 32a in the lateral direction L2 results.

[0089] Fig. 4 shows a further embodiment in which a trench insulation structure 10' has the trench insulation base wall 30, which just as in the embodiment of Fig. 3, it is suitable to provide electrical insulation between the first active component area 20 and the second active To enable area 22.

[0090] The trench insulation sections 32b provided here are arranged in such a way as to allow a high degree of flexibility when enlarging the resulting total side wall.

[0091] In the illustrated embodiment, the trench insulation sections 32b are provided as elongated sections, i.e., rectangular. The direction of extension or orientation Le of the main extension runs in the second lateral direction L2. The trench isolation sections 32b can This allows their length to be varied, while maintaining a minimum distance along the first lateral direction L1. can. Given a minimum distance between the respective adjacent sections 32b, which is typically determined by technological or Since process engineering requirements cannot be undercut, an enlargement of the electrically conductive side wall sections is possible. 14b can be achieved by increasing a length in the second lateral direction L2 (as the main direction of extension), so that a desired thickening of the entire side wall (shown in the section as a top view) and thus the correspondingly increased volume of the The entire side wall will be preserved.

[0092] As also shown in Fig. 3, three electrically conductive side walls are provided in the extension direction of the trench insulation base wall 30: On both sides of the base wall 30 the electrically conductive side walls 14' and 14 and facing away from the base wall 30 the outer electrical Conductive side wall, which here is also a continuous 14" side wall. Between the electrically conductive side walls 14' and 14" The conducting side wall sections 14b extend between adjacent but spaced-apart trench isolation sections 32b, which They in turn maintain a distance b from the trench isolation base wall 30.

[0093] Here too, as in Fig. 3, the structure of the [unclear text] is shown with two vertical sections Q41 and Q42 in Figs. 4a and 4b. Trench isolation structure designed in the direction of L2.

[0094] Functionally, the entire area to the left of the insulating base wall 30 is the electrically conductive side wall, which is shown in the view of Fig. 4 (from above) can also be explained as having a "wall base", although the wall surface of the side wall is more vertical It would be viewed from an oriented perspective. It is then the bottom surface or a horizontal cross-sectional surface of the entire side wall that is defined by the formation of the Fig. 4 is considerably enlarged, as is the corresponding volume in the three-dimensional view.

[0095] In an embodiment not shown separately, the examples of Fig. 3 and Fig. 4 are mixed, i.e., the several Trench isolation sections, extended sections 32a and 32b, which extend with their main direction Le along both the first lateral extending in the direction of L1 as well as along a second lateral direction L2, with the second lateral direction L2 diverging from the first lateral direction This differs. This can be done in groups, or continuously alternating with each trench isolation section.

[0096] The several trench insulation sections 32a ,32b are assigned electrically conductive side wall sections 14b.

[0097] Each trench insulation section is enclosed by two sections of the electrically conductive side walls 14' ,14" and by two electrically conductive sidewall sections 14a or 14b , to form the extended electrically conductive sidewall

[0098] Fig. 5 schematically shows a top view or layout of the semiconductor device 100 in a further advantageous embodiment, in a trench insulation structure of 10" is used. The trench insulation sections become part of the trench insulation base wall 30. Or, viewed another way, the trench isolation sections are omitted and the trench isolation base wall changes its direction in sections. Trench isolation base wall 30 continues to extend continuously, but in alternating directions, in particular in sections or alternately.

[0099] The trench insulation base wall 30 is assigned one, preferably two, electrically conductive side walls, e.g. one electrically conductive Side wall 14, which runs in a straight line, and another electrically conductive side wall 14e, which corresponds to the changing directions of the Trench isolation base wall 30 follows.

[0100] In the example, the alternating directions are the two lateral directions L1 and L2. In Fig. 5, a U is formed on the left from the Sections 30", 30' and 30" of the trench insulation base wall 30, and following this a U of electrically conductive side wall sections 14e", 14e' and 14e" . An inverted U can be added, and several of these geometries can be added in the lateral direction L1.

[0101] The arrangement shown in Fig. 5 can also be described as follows: an “originally” straight section 30 It is folded accordingly, resulting in this simplified meandering course made up of opposing U-elements.

[0102] The structure of the simplified meander or the lengths of the sections 30' and 30" can be chosen such that Due to the processing for the production of the conductive sidewall areas, corresponding areas 14g of the electrically conductive sidewall "grow together", so that on the side of the second component area 22 a more or less straight (right) edge with The corresponding fingers are obtained as electrically conductive sidewall sections (14g), while on the other hand, on the side of the first component area 20 the simplified meander shape is retained.

[0103] The second electrically conductive side wall 14 can have electrically conductive extensions 14g extending from the second electrically conductive side wall exit and extend in the second lateral direction (L2). They intersect the U-shaped curve of the simplified meander, each opening to the right.

[0104] In other embodiments not shown, the sections 30' and the sections 30" can be at other angles It should be provided that, for example, a zigzag arrangement results, in which a first section and a second section are each located under a acute angles are connected to each other. In other embodiments, sections 30' and 30" can be joined together as rounded or rounded components are provided in such a way that an almost wave-like design of the trench insulation base wall 30 is achieved in conjunction with its sections 30' and 30" results. In any case, a significantly larger electrically conductive side wall is obtained, compared to the conventional arrangement shown in Fig. 1 with the two side walls 14 .

[0105] Fig. 6 shows a further arrangement of the semiconductor device 100 with a trench insulation structure 10* , wherein the trench insulation- The base wall has 30 insulating extensions 30c and 30d, which in the illustrated embodiment are designed as extended trench insulation sections. are, on both sides, and are each insulatedly connected to the trench insulation base wall 30, i.e., connected to it or into it flow into each other.

[0106] Two electrically conductive side walls 14c and 14d are provided, which can have alternating directions section by section, as in The first fingers 30c, 30d from below can be seen. Electrically conductive sidewall sections 14c', 14c", 14c' or 14d', 14d", 14d' encompass the first fingers projecting away from the insulating base wall 30c , 30d .

[0107] The distance between the respective sections 30d in the first lateral direction L1 can be determined such that, for example, Electrically conductive side wall sections 14d* result, which fuse or combine. This creates a correspondingly longer straight section. Section 14d' as an electrically conductive side wall.

[0108] With larger selected distances, electrically conductive side wall sections result, which correspond to the outer course of the respective sections. (the projecting fingers) 30c are followed, as is shown, for example, throughout on the side of the first component area 20. Right In active area 22 a comb shape 14d' , 14d* is shown, consisting of electrically conductive sidewall sections and trench insulation sections.

[0109] These geometries can also follow one another, as shown at the bottom right with trench insulation section 30d and the electrically conductive Side wall sections 14d', 14d", 14d' are shown. Likewise, trench insulation section 30c and the electrically conductive side wall sections are shown at the bottom left. Sections 14c' ,14c" ,14c' .

[0110] Of course, two or more of the geometric arrangements described above can be used in the layout of the trench isolation structure 10 They can be combined, including left and right. However, the previously shown variations offer an easy-to-implement geometric form in the layout, which which can then also be efficiently transferred into the semiconductor material using known processes.

[0111] The manufacture of the semiconductor devices 100 described above is accomplished by first creating a suitable layout for the trench insulation structure 10, in which generally an enlarged electrically conductive side wall with the Trench isolation structure is made possible.

[0112] Based on this layout, appropriate lithography masks can be created to create corresponding trenches using known methods. Methods for producing. After applying a suitable lithography mask to the semiconductor material, e.g. a silicon-based disk, wherein the Since the mask essentially replicates the previously created layout, corresponding grooves are etched into the substrate material, e.g., a silicon material. or another suitable semiconductor material extending to a desired depth, for example up to or in or through a buried Extend the insulation layer.

[0113] The etching process creates the corresponding side walls with the enlarged outline length and thus - depending on the Depth – increased volume, which is intended to have a correspondingly reduced conductivity. As explained previously, this is addressed in some Embodiments include a layer of suitable material or materials, e.g. an insulating material, with a suitable layer thickness and with a High concentrations of dopant are deposited, so that the previously formed trenches are lined accordingly. Undesired material of the The layer at the bottom of the trench can be removed by anisotropic etching. Similarly, the material outside the trenches can be removed.

[0114] After the deposition of the doped material, a corresponding heat treatment is carried out at a suitable point in the overall process. performed with parameters that are in accordance with the temperature-time budget, so that a corresponding penetration depth of the dopants is achieved. and A corresponding dopant concentration will be obtained.

[0115] In contrast to the conventional strategy, a larger amount of conductive material is required for the larger overall sidewall. Achieving increased conductivity with otherwise identical process parameters for diffusion has been achieved. The same applies if conductivity is increased by The implantation of ions into the exposed trenches is achieved. That is, by using suitable implantation parameters in the form of dose. and angles, which, as explained above, are subject to certain restrictions, a corresponding doping can be achieved, whereby here too This in turn contributes to the enlarged overall side wall with a larger volume of the resulting conductive material.

[0116] Due to the larger side wall and thus the increased volume of the conductive material in the respective trench insulation structure 10 (also: isolation trench structure) can thus be a high-quality connection, in the sense of low resistance, to buried conductive layers or doped semiconductor layers are produced. The additional "area consumption" due to the new geometry of the Trench isolation structure negligible or at least significantly smaller compared to the effort that would be required to implement a corresponding to create low-resistance connections between buried layers using specially designed connection structures. Furthermore, by The design of the trench isolation structures does not require any additional process steps compared to conventional strategies, such as... They are described, for example, in conjunction with Fig. 2, so that a high degree of compatibility with existing processes is maintained. whereas, on the other hand, a high degree of flexibility for adjusting the setting is only possible by adapting the layout of the trench isolation structure. The desired conductivity is achieved. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was generated automatically and is solely for the better information of the Readers' contributions were included. The list is not part of the German patent or utility model application. The DPMA assumes no liability whatsoever. for any errors or omissions. Cited patent literature

[0000] US 5734192 A

[0013] US 6394638 B1

[0013] US 9385190 B2

[0013] US 5283461

[0013] US 4676847

[0014] US 5013673

[0015] US 5047359

[0015] US 6509240

[0015]

Claims

[1] Semiconductor device with a first active component region (20) and with a second active region (22), wherein the first active component region (20) and the second active area (22) extends over a wide area and along a first lateral direction (L1) and a second, deviating direction extend in the lateral direction (L2); and with - a trench isolation structure (10,10') separating the first active component area (20) from the second active area (22) along the first lateral Direction (L1) is electrically insulated and has at least one electrically conductive side wall (14, 14', 14"); wherein the trench insulation structure (10) exhibits - a trench isolation base wall extending continuously in an insulating manner (30); - and several spaced-apart trench insulation sections (32a, 32b) with electrically conductive sidewalls located between them- Sections (14a,14b); - wherein the multiple trench insulation sections (32a, 32b) and the electrically conductive sidewall sections (14a, 14b) are separated from the base wall (30) are spaced apart (a,b). [2] Semiconductor device according to claim 1, wherein the multiple trench insulation sections are extended sections (32a) which are connected by a Extend the main extension direction (Le) along the first lateral direction (L1). [3] Semiconductor device according to claim 1, wherein the multiple trench insulation sections are extended sections (32b) that align with a Extend the main direction of extension (Le) in the second lateral direction (L2). [4] Semiconductor device according to claim 1, wherein the multiple trench insulation sections are extended sections (32a, 32b) which align with their The main extension direction (Le) extends both along the first lateral direction (L1) and along a second lateral direction (L2), where the second lateral direction (L2) differs from the first lateral direction. [5] Semiconductor device according to one of the preceding claims, wherein the multiple trench insulation sections (32a, 32b) are made of electrically conductive side wall sections and sections of the electrically conductive side walls (14', 14", 14a, 14b) are enclosed to form an extended electrically conductive side wall. [6] Semiconductor device according to one of the preceding claims, wherein the extended sections (32a, 32b) are at least on one side of the first active component area (20) are formed and the first component area has at least one semiconductor component (20a) to be isolated. [7] Semiconductor device according to one of the preceding claims, wherein the electrically conductive sidewalls and sidewall sections (14,14',14",14a, 14b) exhibit doped semiconductor material. [8] Semiconductor device according to any one of claims 1 to 6, wherein the electrically conductive sidewalls and sidewall sections are metal- contain material. [9] Semiconductor device according to one of the preceding claims, wherein the trench insulation structure (10, 10') extends in a depth direction up to a is formed in a buried insulation layer (4). [10] Semiconductor device according to one of the preceding claims, wherein one or more of the conductive sidewalls and one or more the conductive sidewall sections on the side of the first active component area (20) with a first buried, conductive layer (6a) in the first The component area is connected. [11] Semiconductor device according to one of the preceding claims, wherein one or more of the conductive sidewalls and one or more the conducting sidewall sections on one side of the second active area (22) with a second buried conducting layer (6) in the are connected to the second active area. [12] Semiconductor device according to one of the preceding claims, wherein the second active region (22) is also an active device region. [13] Semiconductor device according to one of the preceding claims, wherein the trench insulation base wall (30) is sectionally in the first lateral direction (L1) and in the second lateral direction (L2). [14] Semiconductor device according to any one of the preceding claims 2 to 13, wherein the elongated trench insulation sections (32a, 32b) are rectangular are trained. [15] Semiconductor device with a first active component area (20) and with a second active component area (22), wherein the first active component area (20) and the second active area (22) extend along two lateral directions (L1,L2); and with - a trench isolation structure (10*) that separates the first active component area (20) from the second active area (22) along a first (L1) of the two electrically insulated in lateral directions and has at least one electrically conductive side wall (14c,14d); - where the trench isolation structure (10*) further exhibits -- a trench isolation base wall (30) extending in the first lateral direction (L1); -- and several trench insulation sections (30c, 30d) with associated electrically conductive sidewall sections (14c',14c",14d',14d"); -- wherein the multiple trench isolation sections connect to the trench isolation base wall (30). [16] Semiconductor device according to claim 15, wherein the trench isolation structure (10*) which separates the first component area (20) from the second active The area (22) is electrically insulated along the first lateral direction (L1) and has two continuously electrically conductive side walls (14c,14d). [17] Semiconductor device according to claim 15, wherein the multiple trench insulation sections (32c, 32c; 32d, 32d) are located on both sides of the Connect trench insulation base wall (30). [18] Semiconductor device according to one of the preceding claims 15 or 16, wherein the multiple trench insulation sections (32c, 32d) are located at the Connect trench insulation base wall (30) on one side. [19] Semiconductor device according to any one of the preceding claims 15 to 18, wherein electrically conductive sidewall sections (14d") of adjacent Trench insulation sections (30d,30d) are merged or combined into a common side wall section (14d*). [20] Semiconductor device according to any one of the preceding claims 15 to 19, wherein the electrically conductive side wall sections (14c",14d") - project finger-like into the second of the two lateral directions (L1,L2) at the trench isolation sections (32c,32d); or - combine to form a conductive simplified meander structure (14c',14c",14c'); or - form a combination of both in one extension direction of the trench isolation base wall (30). [21] Semiconductor device according to any one of the preceding claims 15 to 20, wherein the electrically conductive sidewall sections (14c',14c",14c') at least in some areas they alternate in both lateral directions (L1,L2). [22] Semiconductor device according to any one of the preceding claims 15 to 21, wherein the trench insulation sections (30c, 30d) are extensions of the Trench isolation base wall (30) are formed. [23] Semiconductor device with a first active component area (20) and with a second active area (22), wherein the first active component area (20) and the second active area (22) extend along a first lateral direction (L1) and along a second lateral direction (L2); and with - a trench isolation structure (10") that separates the first active component area (20) from the second active area (22) along the first lateral direction (L1) electrically insulated and has at least one electrically conductive side wall (14e,14); - where the trench isolation structure (10") further exhibits -- extending section by section in the first lateral direction (L1) and section by section in the second lateral direction (L2) Trench insulation base wall (30;30',30"); - wherein the electrically conductive side wall (14e) has sections extending along the first lateral direction (L1) and the second lateral Extend in the direction (L2). [24] Semiconductor device according to claim 23, wherein the different directions for the trench insulation base wall (30;30',30") a simplified meander shape results from opposing U-shapes, or it acquires such a geometry, and the trench isolation Base wall (30) the active areas (20,22) are continuously isolated from each other. [25] Semiconductor device according to claim 23 or 24, wherein the trench insulation base wall (30) provides continuous insulation and the electrically conductive side wall (14e) is conductive throughout. [26] Semiconductor device according to one of the preceding claims, wherein the trench insulation structure (10") is a second continuous, electrically conductive has a side wall (14) that extends in the first lateral direction (L1). [27] Semiconductor device of claim 26, wherein the second electrically conductive side wall (14) is located on another side of the trench insulation base wall (30) is arranged. [28] Semiconductor device of claim 27, wherein the second electrically conductive side wall (14) has electrically conductive extensions (14g) which are separated from the exit the second electrically conductive side wall and extend in the second lateral direction (L2). [29] Semiconductor device according to the preceding claim 28, wherein the second electrically conductive side wall (14) has a trench insulation Base wall (30) has a straight edge pointing away from the ground. [30] Method for manufacturing a semiconductor device, comprising the following steps - Providing a layout of a first active component area from a second active area (20, 22) electrically insulating trench insulation structure (10, 10'); - wherein an entire electrically conductive side wall of the trench insulation structure is provided by insulation trench sections (32a;32b;30c,30d) with electrically conductive sidewall sections (14a, 14b, 14c"), in addition to a length in the direction of extension of the Trench isolation structure (10, 10') running isolation trench base wall (30); - Manufacturing the semiconductor device using the created layout. [31] Method according to claim 30, wherein in the layout the isolation trench sections are provided such that at least some Isolation trench sections are spaced from the base wall by conductive sidewall sections or a conductive sidewall (14'). [32] Method according to claim 30 or 31, wherein in the layout the isolation trench base wall is constructed from straight pieces, the The first component area is enclosed by an insulating trench wall, and the isolation trench sections are at least on one side of the first active component area (20) are arranged. [33] Method according to any of the preceding claims 30 ff, wherein the isolation trench sections are elongated elements with a main- Extension direction is provided, and its orientation runs perpendicular to an extension direction of the isolation trench base wall (30). [34] Method according to any one of the preceding claims 30 et seq., wherein the isolation trench sections are elongated elements with a main- Extension direction is provided, and its orientation runs parallel to an extension direction of the isolation trench base wall (30). [35] Method according to any of the preceding claims 30 ff, wherein in the layout the isolation trench sections (30c, 30d) are provided such that at least some isolation trench sections are connected to the isolation trench base wall (30) via an insulating material. [36] Method according to any one of the preceding claims 30 ff, wherein at least some isolation trench sections are formed as extensions (30c, 30d) of the Isolation trench base wall (30) is designed, with which at least some isolation trench sections are insulatedly connected. [37] Method according to any one of the preceding claims 30 et seq., wherein the manufacturing is carried out such that an entire electrically conductive side wall is covered with electrically conductive side wall sections are created as an electrically conductive volume. [38] Method according to any one of the preceding claims 30 et seq., wherein the production is carried out such that a buried insulating layer (4) is placed under the first active component area (20) and / or below the second active area (22) touches a lower end of the electrically conductive volume.

Images