DE102019117561B4 - Electronic component with a breakdown voltage that can be defined as a result of the manufacturing process - Google Patents

Abstract

An electronic component with a breakdown voltage that can be defined by its layout, in particular for protecting electronic components and / or circuits, has a semiconducting substrate with an upper substrate layer (20) which is an extremely weakly doped, grown-on semiconductor material. If an active area is now implanted in this semiconductor material, with the area in which the PN junction will later be formed being cut out during the implantation, an extremely weakly doped tub sub-area (32) with a collector is created after the thermal outdiffusion in said area -Area (34) is placed. An emitter region (38) and a base region (40) are formed in the remaining region of the well region (24). The connection of this bipolar transistor as a diode makes it possible to define the breakdown voltage of the diode through the geometric configuration of the photo masks.

Description

The invention relates to an electronic component with a breakdown voltage that can be defined as a result of the manufacture, namely through the design of photomasks, wherein the electronic component can be used in particular to protect electronic components and / or circuits from functional impairment by externally caused overvoltages.

The protection of electronic components and / or electronic circuits from functional impairments, in particular from externally applied overvoltages, is an essential requirement for integrated circuits, the higher the degree of integration of the circuit, the higher the protection requirements. For this purpose, the external connections of an IC must be switched to ground or another current-stable reference point by a protective diode or an electronic component designed as a protective diode. It is essential that the protective diode switches through reversibly if necessary. In this context, it is desirable if the breakdown voltage can be adjusted through the geometric design of the photomasks used for the protective diode.

Examples of such protective diodes or of electronic components operated as protective diodes are given in DE 10 2014 009 032 B4 and DE 10 2008 005 932 A1 described.

In order to be able to guarantee the breakdown voltage even in a high voltage range, an overvoltage protection diode should have a comparatively wide space charge zone. In the prior art, this is achieved by appropriately lightly doped p and n regions, with the result that the PN junction has a space charge zone of the required width. The in DE 10 2014 009 032 B4 For this purpose, the proposed ESD protection diode is proceeded in such a way that the area in which the PN junction is formed is spared during the ion implantation, which results in a weakly doped area during the subsequent thermal diffusion. The object of the invention is to simplify the manufacturing process of an electronic component with a breakdown voltage that can be defined through the targeted use of photomask steps available in semiconductor process technology.

• - einem halbleitenden Substrat mit einer ersten Substratschicht, die epitaktisch gewachsenes erstes Halbleitermaterial aufweist, welches schwach dotiert und von einem ersten Leitungstyp ist, und mit einer auf der ersten Substratschicht angeordneten zweiten Substratschicht, die ein zweites Halbleitermaterial aufweist, das sehr schwach dotiert epitaktisch auf dem ersten Halbleitermaterial der ersten Substratschicht aufgewachsen und von einem zum ersten Leitungstyp inversen zweiten Leitungstyp ist, wobei die zweite Substratschicht ein mit der ersten Substratschicht verbundenes unteres Ende und eine diesem abgewandte, die Oberseite des Substrats bildende Oberseite aufweist,
• - einem sich von der Oberseite des Substrats aus in die zweite Substratschicht hinein erstreckenden, schwach dotierten Wannengebiet vom zweiten Leitungstyp, dessen Tiefe geringer ist als die Dicke der zweiten Substratschicht,
• - einem an der Oberseite des Substrats angeordneten und sich in das Wannengebiet hinein erstreckenden, stark dotierten Basis-Gebiet vom zweiten Leitungstyp,
• - einem an der Oberseite des Substrats angeordneten und sich in das Wannengebiet mit Abstand zu dem Basis-Gebiet hinein erstreckenden, stark dotierten Emitter-Gebiet vom ersten Leitungstyp,
• - einem an der Oberseite des Substrats angeordneten und sich in das Wannengebiet mit Abstand zu sowohl dem Emitter-Gebiet als auch dem Basis-Gebiet hinein erstreckenden, stark dotierten Kollektor-Gebiet vom ersten Leitungstyp,
• - wobei die Basis-, Emitter- und Kollektor-Gebiete an der Oberseite des Substrats voneinander elektrisch isoliert sind,
• - wobei sich innerhalb des Wannengebiets und unterhalb des Kollektor-Gebiets sowie seitlich um dieses herum ein Wannenteilgebiet vom zweiten Leitungstyp befindet, das schwächer dotiert ist als das Wannengebiet und das sowohl von dem Basis-Gebiet als auch von dem Emitter-Gebiet beabstandet ist,
• - wobei die Ausdehnung und/oder Dotierung des Wannenteilgebiets die Durchbruchspannung definiert,
• - wobei das Kollektor-Gebiet einen ersten Anschluss bildet und
• - wobei das Emitter-Gebiet elektrisch mit dem Basis-Gebiet verbunden ist und beide einen zweiten Anschluss bilden.

To solve this problem, the invention proposes an electronic component with a definable breakdown voltage for protecting electronic components and / or circuits from impairment of function due to overvoltages, the electronic component being provided with

• - A semiconducting substrate with a first substrate layer which has epitaxially grown first semiconductor material, which is weakly doped and of a first conductivity type, and with a second substrate layer arranged on the first substrate layer, which has a second semiconductor material which is very weakly doped epitaxially on the first semiconductor material of the first substrate layer and is of a second conduction type that is inverse to the first conduction type, the second substrate layer having a lower end connected to the first substrate layer and an upper side facing away from this and forming the upper side of the substrate,
• - A weakly doped well region of the second conductivity type extending from the top of the substrate into the second substrate layer, the depth of which is less than the thickness of the second substrate layer,
• a heavily doped base region of the second conductivity type, which is arranged on the top side of the substrate and extends into the well region,
• a heavily doped emitter region of the first conductivity type, arranged on the top side of the substrate and extending into the well region at a distance from the base region,
• a heavily doped collector region of the first conductivity type, which is arranged on the upper side of the substrate and extends into the well region at a distance from both the emitter region and the base region,
• - The base, emitter and collector regions on the top of the substrate are electrically isolated from one another,
• - wherein a well sub-region of the second conductivity type is located within the well region and below the collector region and laterally around it, which is less doped than the well region and which is spaced apart from both the base region and the emitter region,
• - wherein the expansion and / or doping of the well sub-area defines the breakdown voltage,
• - wherein the collector region forms a first connection and
• - The emitter region being electrically connected to the base region and both forming a second connection.

The electronic component according to the invention is designed as a component formed in a semiconducting substrate, the breakdown voltage of which is defined by the geometric design of the photomasks available in the semiconductor process and can thus be determined from a manufacturing point of view, a special type of substrate being used. The substrate in which the electronic component according to the invention is integrated has a first substrate layer which is weakly doped and of a first conductivity type. The first substrate layer can for example have epitaxially grown silicon. The first conduction type can be the p conduction type, for example.

A second substrate layer is epitaxially grown on this first substrate layer, this second substrate layer having grown semiconductor material of a second conductivity type. This second semiconductor material is grown as a semiconductor material of the second conductivity type, so it is not doped or the like after the growth. The two substrate layers are grown together (in one piece), the second substrate layer forming the top of the substrate.

According to the proposal according to the invention, an epitaxially grown p- or n-doped semiconductor material is used as the upper second substrate layer. Such semiconductor substrates are known in principle and can be used with advantage for the production of the electronic component according to the invention.

The dopant for a well region is now implanted into the weakly doped second semiconductor material of the second substrate layer. The area of the tub area in which the PN junction is to arise later is left out of the implantation. In this way, two partial wells are initially created which, after out-diffusion, grow together to form the well area which forms the active area in and below the top of the substrate. After outdiffusion, the well region thus has a well sub-region in which the dopant concentration is significantly reduced compared to the rest of the well region and this is due to the fact that the well region is formed in the already very weakly doped, epitaxially grown second semiconductor material of the second substrate layer, is extremely weakly doped.

A heavily doped collector region of the first conductivity type, that is to say of a conductivity type opposite to the conductivity type of the well region, is then additionally formed in the well sub-region. While this collector area is located within the well subarea below the top side of the substrate, a base and an emitter area are also located in and below the top side of the substrate, spaced apart from this collector area in the well area. These two areas are electrically isolated from one another, which also applies to the relationship between the collector area and the two aforementioned areas. All three areas mentioned above are therefore electrically isolated from one another in the substrate.

The transition from the well sub-region to that region of the well region in which the emitter and base regions are formed is located between the collector region and the emitter region or between the collector region and the base region.

The collector region forms a first connection of the electronic component according to the invention, the second connection of which is realized by electrically connecting the base and emitter regions. The first connection can also be referred to as the anode connection and the second connection as the cathode connection.

By integrating the, for example, p-doped collector region into the very weakly n-doped tub sub-region, a PN junction arises in this tub sub-region with a space charge zone projecting comparatively far into the tub sub-region starting from the collector region. As a result, comparatively high breakdown voltages can be achieved solely by layout measures (namely the width of the area on the upper side of the substrate that is not ion-implanted), with the addition of a semiconductor material that is very weakly doped as a substrate to simplify the manufacturing process Semiconductor material has grown epitaxially.

With regard to the ratios of the dopant concentrations (doping) of the individual regions of the electronic component according to the invention, it can advantageously be provided that the collector, emitter and base regions are most heavily doped, that the well region is weaker than the collector, emitter and base Regions is doped, that the well sub-region is doped more weakly than the well region and that the second substrate layer of the substrate has an electrical resistance which can be represented by a doping that is equal to or less than the doping of the well sub-region.

A first and a second type of line were mentioned above. The first conductivity type can be the p conductivity type and the second conductivity type can be the n conductivity type, or the first conductivity type can be the n conductivity type and the second conductivity type can be the p conductivity type.

As already mentioned above, the space charge zone mainly spreads in the tub subarea around the collector area. To symmetrize the space charge zone so that it extends into both areas of the PN junction, it is proposed within the scope of a further development of the invention that a lightly doped additional well area of the first conductivity type be provided within the well sub-area and below the collector area and laterally around it is trained. In this embodiment of the invention, the comparatively heavily doped collector region is surrounded by a weakly doped additional well region, which in turn is arranged in the partial well region. This creates a doping gradient from the heavily doped collector region via the more weakly doped additional well region to its boundary with the partial well region and thus a symmetrization of the space charge zone.

Typically, the additional well region is doped more weakly than the collector region and / or the additional well region is doped as weakly as, or more weakly, or more heavily than the well sub-region.

As already described above, the base, emitter and collector regions are electrically isolated within the substrate. This is typically achieved in that electrically insulating insulation regions are formed on the top of the substrate between the base, emitter and collector regions and protrude into the well region, the insulation regions adjoining the collector region into the well subregion and, if present, protrude into the additional tub area.

In a further expedient embodiment of the invention it is typically provided that the tub sub-region has a first depth and that the tub region outside the tub sub-region has a second depth that is greater than the first depth but smaller than the thickness of the second substrate layer.

In the concept according to the invention, the breakdown voltage is thus determined by photomasks which define the geometry of the electronic component. In relation to the design of the electronic component, the extent of the tub sub-area in its width and / or depth and / or the doping of the tub sub-area defines the switching threshold from which, when a reverse voltage is applied between the first connection and the second connection in the tub area and the tub sub-area a current flows due to an avalanche breakdown.

With regard to the substrate of the electronic component according to the invention, it typically applies that the first semiconductor material, viewed independently of its doping, and the second semiconductor material, viewed regardless of its doping, are the same or different. Both semiconductor materials can be silicon or germanium or silicon carbonate, for example.

The bipolar transistor designed according to the invention and connected as a lateral diode can be expanded as an integrated antiserial arrangement (by a common base and electrically conductively connected emitter), whereby an electronic component with two identical or different positive as defined by the geometric configuration of the photomasks negative breakdown voltages arise. The advantage of such a component for protecting electronic components and / or circuits from functional impairment due to overvoltages is that there is now protection against both positive and negative overvoltages. Such a protective component can be used in particular in bus applications that require a ground offset between the bus users. The advantage of the expansion of the electronic component according to the invention is that two different “polarized” breakdown voltages can now be defined in a controlled manner by the geometric configuration of the photomasks used.

• - einem halbleitenden Substrat mit einer ersten Substratschicht, die epitaktisch gewachsenes erstes Halbleitermaterial aufweist, welches schwach dotiert und von einem ersten Leistungstyp ist, und mit einer auf der ersten Substratschicht angeordneten zweiten Substratschicht die ein zweites Halbleitermaterial aufweist, das sehr schwach dotiert epitaktisch auf dem ersten Halbleitermaterial der ersten Substratschicht aufgewachsen und von einem zum ersten Leitungstyp inversen zweiten Leitungstyp ist, wobei die zweite Substratschicht ein mit der ersten Substratschicht verbundenes unteres Ende und eine diesem abgewandte, die Oberseite des Substrats bildende Oberseite aufweist,
• - einem sich von der Oberseite des Substrats aus in die zweite Substratschicht erstreckenden, schwach dotierten Wannengebiet vom zweiten Leitungstyp, dessen Tiefe geringer ist als die Dicke der zweiten Substratschicht,
• - einem an der Oberseite des Substrats angeordneten und sich in das Wannengebiet hinein erstreckenden, stark dotierten Basis-Gebiet vom zweiten Leitungstyp,
• - zwei an der Oberseite des Substrats angeordneten und sich in das Wannengebiet mit Abstand zu dem Basis-Gebiet erstreckenden stark dotierten Emitter-Gebieten vom ersten Leitungstyp, zwischen denen das Basis-Gebiet angeordnet ist, und
• - zwei an der Oberseite des Substrats ausgebildeten und sich in das Wannengebiet mit Abstand zu sowohl dem Basis-Gebiet als auch den Emitter-Gebieten hinein erstreckenden, stark dotierten Kollektor-Gebieten vom ersten Leitungstyp, zwischen denen die beiden Emitter-Gebiete und das Basis-Gebiet angeordnet sind,
• - wobei die Basis-, Emitter- und Kollektor-Gebiete an der Oberseite des Substrats voneinander elektrisch isoliert sind,
• - wobei sich innerhalb des Wannengebiets und unterhalb jedes Kollektor-Gebiets sowie seitlich um jedes der Kollektor-Gebiete herum jeweils ein Wannenteilgebiet vom zweiten Leitungstyp befindet, wobei beide Wannenteilgebiete schwächer dotiert sind als das Wannengebiet,
• - wobei jedes Wannenteilgebiet sowohl von dem Basis-Gebiet als auch von dem zu ihm benachbarten Emitter-Gebiet beabstandet ist,
• - wobei das eine Kollektor-Gebiet einen ersten Anschluss und das andere Kollektor-Gebiet einen zweiten Anschluss bildet und
• - wobei die beiden Emitter-Gebiete und das Basis-Gebiet untereinander elektrisch verbunden sind.

The electronic component in the integrated anti-serial constellation with a common base and electrically connected emitters is provided according to the invention with

• - A semiconducting substrate with a first substrate layer which has epitaxially grown first semiconductor material which is lightly doped and of a first power type, and with a second substrate layer arranged on the first substrate layer which has a second semiconductor material which is very lightly doped epitaxially on the first Semiconductor material of the first substrate layer is grown on and is of a second conductivity type that is inverse to the first conductivity type, the second substrate layer having a lower end connected to the first substrate layer and an upper side facing away from this and forming the upper side of the substrate,
• - A weakly doped well region of the second conductivity type extending from the top of the substrate into the second substrate layer, the depth of which is less than the thickness of the second substrate layer,
• - one arranged on the upper side of the substrate and extending into the well area extending, heavily doped base region of the second conductivity type,
• two heavily doped emitter regions of the first conductivity type which are arranged on the upper side of the substrate and extend into the well region at a distance from the base region and between which the base region is arranged, and
• - Two heavily doped collector regions of the first conductivity type, formed on the top of the substrate and extending into the well region at a distance from both the base region and the emitter regions, between which the two emitter regions and the base Area are arranged,
• - The base, emitter and collector regions on the top of the substrate are electrically isolated from one another,
• - a well sub-area of the second conductivity type being located within the well region and below each collector region and laterally around each of the collector regions, with both well sub-regions being less doped than the well region,
• - each well sub-region being spaced apart from both the base region and the emitter region adjacent to it,
• - wherein one collector region forms a first connection and the other collector region forms a second connection
• - The two emitter regions and the base region are electrically connected to one another.

With the integrated anti-serial arrangement of the electronic component, two PN junctions are created, one of which switches through when the switching threshold (positive and negative voltage) determined by the design is reached, the other PN junction then being traversed by current in the forward direction. By choosing the geometry or dimensions of the two tub subareas, it is now possible, if necessary, to define breakdown voltages with different amounts. However, it is also possible to define the breakdown voltages to be of the same magnitude.

In connection with the electronic component in the integrated anti-serial arrangement, it is typically such that the collector regions and the base region are most heavily doped, that the well region is less doped than the collector, emitter and base regions, that the two well subareas are equally weakly or differently weakly doped and each well subarea is more weakly doped than each of the well regions and that the second substrate layer of the substrate has an electrical resistance that can be represented by a doping that is equal to or less than the doping of each of the Tub areas is.

It also applies to the variant of the invention with integrated anti-serial arrangement of the electronic component that the first conduction type is the p conduction type and the second conduction type is the n conduction type or the first conduction type is the n conduction type and the second conduction type is the p conduction type.

To symmetrize at least one of the two PN junctions of the electronic component in the integrated antiserial arrangement, a lightly doped additional well region of the first conductivity type is formed within at least one of the well subregions and below the relevant collector region and around it.

It is advantageous here that a weakly doped additional well region of the first conductivity type is formed within each well sub-region and below the relevant collector region and laterally around it, and that the doping of both additional well regions is equally or differently weak.

Furthermore, in the two aforementioned embodiments of the invention, it can be provided that at least one of the additional well regions or each additional well region is less doped than the respective collector region which is arranged in the relevant additional well region.

Even with the variant as an integrated anti-serial arrangement of the electronic component, it is typically the case that electrically insulating isolation areas are formed on the top of the substrate between the base, emitter and collector areas, which protrude into the tub sub-area, with those on the collector area adjacent isolation areas protrude into the tub sub-area and, if available, into the additional tub area.

In the case of the integrated anti-serial arrangement of the electronic component, it is also typically provided that each well sub-region has a first depth and that the well region outside of each well sub-region has a second depth which is greater than the first depth and smaller than the thickness of the second substrate layer. The two tub subareas can have the same or different depths.

For the magnitudes of the breakdown voltages, it typically applies that the extent of each tub sub-area in its width and / or depth and / or the doping of each well sub-region define switching thresholds that are the same or different and from which when a first reverse voltage is applied with a first reverse polarity or when a second reverse voltage is applied with a reverse polarity between the first connection and the second connection in the Tub subareas and in the tub area due to an avalanche breakdown a current flows.

As with the first variant of the invention, it also applies to the second variant of the electronic component according to the invention that the first semiconductor material considered independently of its doping and the second semiconductor material considered independent of its doping are the same or different.

The essential feature of the invention is that an N-EPI (n -) substrate (or, conversely, a P-EPI (p -) substrate) is used as the substrate. This has the advantage that the weakly doped and so far “thinned out” well sub-region remains n-doped (or p-doped) in any case, right into the deepest regions of the well sub-region, which is the case with a p-doped substrate implanted tub area cannot be guaranteed in depth.

The “breakthrough” effect of the electronic component according to the invention is based, as already indicated above, on an avalanche effect.

If, as already described above in connection with the second variant of the invention, in the case of external overvoltages, for example, you want to ensure that voltage pulses with a negative sign relative to the substrate (voltages below substrate potential) are also cushioned and diverted, then two are used in series against one another switched diodes. According to the invention, this integrated anti-serial arrangement has the advantage that the same or different breakdown voltages can now be set for both cases (positive and negative polarity). One of the two diodes is then always switched in the forward direction, while the other is switched in the reverse direction, which makes it possible to initiate the avalanche effect from a breakdown voltage that is set in the manufacturing process. The integrated anti-serial arrangement is used, for example, in order to be able to take into account a potential mass offset of different bus users in bus applications.

Finally, another variant of the invention relates to an integrated anti-serial arrangement of two components of the type described above, in which the two emitter regions are combined to form a common emitter region, the common emitter region being arranged between the two collector regions and wherein the base region is arranged outside the region that is occupied on the top side of the substrate by the arrangement of the common emitter region and the two collector regions.

For the invention, among other things, it is crucial that with the electronic component a structure with adjustable ignition of an n-based (or p-based) avalanche bipolar transistor by means of one or more extremely weakly doped well subregions under and / or on the collector Area and is additionally provided with an optional implantation to further increase the breakdown voltage.

• 1 schematisch die Verschaltung einer Überspannungs-Schutzdiode an einem IC-Anschlusspin,
• 2 eine schematische Darstellung der einzelnen dotierten Gebiete in einem Substrat für die Schutzdiode gemäß 1,
• 3 eine Erweiterung der Schutzdiode gemäß 2,
• 4 eine schematische Darstellung zweier in Serie und verdreht zueinander verschalteter Überspannungs-Schutzdioden,
• 5 die verschiedenen dotierten Gebiete einer Halbleiteranordnung zur Realisierung der integriert antiseriellen Anordnung gemäß 4,
• 6 eine erste Erweiterung der integriert antiseriellen Anordnung gemäß 5,
• 7 eine weitere Ergänzung/Erweiterung der integriert antiseriellen Anordnung gemäß 5 bzw. 6 und
• 8 eine zu den 5 bis 7 alternative Ausführung einer integriert antiseriellen Anordnung.

The invention is explained in more detail below on the basis of several exemplary embodiments and with reference to the drawing. In detail, show:

• 1 schematically the connection of an overvoltage protection diode to an IC connection pin,
• 2 a schematic representation of the individual doped regions in a substrate for the protective diode according to FIG 1 ,
• 3 an extension of the protection diode according to 2 ,
• 4th a schematic representation of two overvoltage protection diodes connected in series and twisted to one another,
• 5 the various doped regions of a semiconductor arrangement for realizing the integrated antiserial arrangement according to FIG 4th ,
• 6th a first extension of the integrated anti-serial arrangement according to 5 ,
• 7th a further addition / extension of the integrated anti-serial arrangement according to 5 or. 6th and
• 8th one to the 5 to 7th alternative design of an integrated anti-serial arrangement.

1 shows schematically the interconnection of an overvoltage protection diode 10 with a connector 12 an integrated circuit. The protection diode 10 is based on positive overvoltages at the connection 12 , in the reverse direction between the connection 12 and mass 14th switched and can be used, for example, for ESD protection.

The layout of the protection diode 10 according to a first embodiment, FIG 2 shown. The Protection diode 10 is designed as a bipolar transistor which is connected as a diode. The diode 10 is in a semiconductor substrate 16 formed that a first substrate layer 18th (in this exemplary embodiment a p-doped epitaxial silicon substrate) and a second epitaxial substrate layer grown on this 20th which in this exemplary embodiment has an N-EPI (n -) silicon substrate, that is to say a very weakly doped semiconductor material.

In the top 22nd of the semiconductor substrate 16 is an n-doped well region through ion implantation 24 implanted, with a surface sub-area 26th during the ion implantation is covered so that two partial tubs 28 , 30th arise. These two sub-tubs grow through thermal diffusion 28 , 30th to the tub area 24 together, with the peculiarity that below the partial surface area 26th a tub subarea 32 arises that extends far into the second substrate layer 20th inside has an extremely weak n-doping.

In the tub subarea 32 is a heavily p-doped collector area 34 implanted and diffused out. This collector area forms the first connection of the diode 10 , which is the anode 36 the diode 10 acts.

In that area of the tub area 24 that from the partial tub 30th is also an emitter area 38 and a base area 40 educated. At the top 22nd of the semiconductor substrate 16 are also isolation areas 41 , 42 , 44 and 46 formed, through which the aforementioned collector, emitter and base regions are electrically isolated from one another. The base area 40 and the emitter area 38 are connected by external wiring as the second connection of the diode and form the cathode 48 the diode 10 . Within the tub sub-area 32 and around the emitter area 38 and the base area 40 having part of the tub area 24 the PN junction of the diode is now formed 10 out. Due to the relatively heavy doping of the collector area 34 and the relatively weakly doped well sub-area 32 the space charge zone expands mainly into the tub area 32 out.

In 2 is shown that the tub area 24 outside the tub sub-area 32 the depth T1 while the depth of the tub sub-area 32 With T2 is less than T1 . Both areas are at a distance from the first substrate layer in their deepest areas 18th on. The tub sub-area 32 extends on both sides of the collector area 34 laterally across this by the distance 50 out.

In the areas 34 , 38 and 40 In other words, it is the respective connection areas of the collector, emitter and base.

To symmetrize the expansion of the PN junction, as in 3 shown, in a modified embodiment in the tub subarea 32 an additional tub area 52 implanted in the same way as the collector area 34 is p-doped, but is less p-doped than the collector region 34 .

In the 2 and 3 AS1 means the distance between the collector area 34 from the PN junction with the base area 40 has, AS1 mostly the space charge zone within which the p- and n-doping are balanced.

In 4th an ESD protection arrangement is shown schematically in an integrated anti-serial diode arrangement. With the IC connector 12 ' an integrated circuit is a diode array 10 ' connected, the second connection to ground 14 ' connected is. The diode arrangement 10 ' has two diodes connected with reverse polarity 10 according to one of the two previously described embodiments. An embodiment for the diode arrangement 10 ' (integrated antiserial arrangement) is in 5 shown.

The dashed line in the middle of the 5 forms an imaginary axis or plane, relative to which the two halves are essentially mirrored. This is especially true for the position of the individual areas of the two diodes 10 the diode array 10 ' , where, as in 5 what can be seen is the geometric dimensions of the areas, in particular of the two tub sub-areas 32 can be different from each other.

In 5 are those components or areas of the respective diodes 10 those of the diode 10 according to 2 same or correspond, with the same reference numerals as in 2 Mistake.

The integrated anti-serial diode arrangement 10 according to 5 has one collector area 34 as anode (connection 36 ) while the other collector area 34 the cathode (connection 48 ) forms. The lateral extension of the two tub areas 32 is in the embodiment according to 5 different, which results in different breakdown voltages of the two diodes due to these two well subregions 10 set or have preset.

In 6th is an alternative embodiment to the diode arrangement 10 ' the 5 shown. In the embodiment according to 6th is in one of the two tub areas 32 an additional tub area 52 implanted as it was for the diode 10 according to 3 is shown. The second Tub subarea 32 the 6th is, however, (still) formed without such an additional well region.

In 7th is finally an embodiment of the integrated anti-series diode arrangement 10 ' shown in which both tub subareas 32 an additional tub area each 52 exhibit.

With regard to the distances AS1 and AS2, the above applies in connection with the distance AS1 of 2 and 3 Said.

The two diodes 10 of the exemplary embodiments for integrated anti-serial arrangement have a common base area 40 that in the layout opposite the emitter areas 38 of the two diodes 10 is isolated, but electrically with these emitter areas 38 is connected externally. The two diodes 10 but can also have base regions isolated in the layout, which are then electrically connected externally to the two emitter regions 38 . About the electrical connection are the two diodes 10 connected in series and in opposite directions. The tub subareas 32 can be the same or different depths T2 , T2 ' have what, moreover, also for the additional tub areas 52 applies or can apply.

8th shows how that 5 to 7th a bidirectional, integrated antiserial arrangement with in contrast to that according to the 5 to 7th outlying base area 40 and common emitter area 38 . In contrast to the exemplary embodiments of 5 to 7th the combination of the two bipolar transistors connected as diodes is (further) integrated with one another. As in both examples of the 5 to 7th can also in the embodiment of 8th the two tub areas 32 geometrically (width, width, depth) be the same or different, which also applies to the two additional tub areas, of which in the embodiment of FIG 8th neither, one, or both can exist.

sehr schwach:

1e+15 bis 1e+16

schwach:

1e+16 bis 1e+17

stark:

1e+17 bis 1e+18

sehr stark:

1e+18 bis 1e+20

If the doping of the individual areas and wells as well as areas of the protective diode or the protective diode arrangement are previously defined as very weak, weak, strong and very strong, according to an exemplary embodiment of the invention, for example, the following value ranges and in the physical unit 1 / cm ³ apply:

very weak:

1e + 15 to 1e + 16

weak:

1e + 16 to 1e + 17

strong:

1e + 17 to 1e + 18

very strong:

1e + 18 to 1e + 20

The doping of the two substrate layers, which are produced by epitaxial growth, can be specified by specifying their respective resistivities as being in the range from 1 Ω / cm to 10 Ω / cm.

These example parameter ranges apply very generally to the substrate materials and dopants usually used in semiconductor technology and are given in particular for the example of p-doping by ion implantation by means of boron and n-doping by ion implantation by means of phosphorus.

List of reference symbols

10

Overvoltage protection diode

10 '

integrated anti-serial diode arrangement

12

connection

12 '

IC connector

14th

Ground reference

14 '

Ground reference

16

Semiconductor substrate

18th

first substrate layer

20th

second substrate layer

22nd

Top

24

Tub area

26th

Partial surface area

28

Partial tubs

30th

Partial tubs

32

Tub subarea

34

Collector area

36

Anode (1st connection)

38

Emitter area

38 '

merged emitter areas

40

Base area,

41

Isolation areas

42

Isolation areas

44

Isolation areas

46

Isolation areas

48

Cathode (2nd connection)

50

distance

52

Additional tub area

T1

Depth of the tub area

T2

Depth of the tub sub-area

T2 '

Depth of the tub sub-area

QUOTED PRINTINGS

• DE 10 2014 009 032 B4
• DE 10 2008 005 932 A1

Claims (21)

Electronic component with a definable breakdown voltage to protect electronic components and / or circuits from impairment of function through overvoltages, with - A semiconducting substrate (16) having a top side (22) with a first substrate layer (18) which has epitaxially grown first semiconductor material which is lightly doped and of a first conductivity type, and with a second layer arranged on the first substrate layer (18) A substrate layer (20) which has a second semiconductor material which is very weakly doped epitaxially grown on the first semiconductor material of the first substrate layer (18) and is of a second conductivity type that is inverse to the first conductivity type, the second substrate layer (20) being one with the first substrate layer (18) has connected lower end and an upper side facing away from this and forming the upper side (22) of the substrate (16), - A weakly doped well region (24) of the second conductivity type, which extends from the top (22) of the substrate (16) into the second substrate layer (20) and whose depth is less than the thickness of the second substrate layer (20), - A heavily doped base region (40) of the second conductivity type, arranged on the upper side (22) of the substrate (16) and extending into the well region (24), - A heavily doped emitter region (38) of the first conductivity type, arranged on the upper side (22) of the substrate (16) and extending into the well region (24) at a distance (50) from the base region (40), - A heavily doped one arranged on the top (22) of the substrate (16) and extending into the well region (24) at a distance (50) from both the emitter region (38) and the base region (40) Collector area (34) of the first line type, - The base, emitter and collector regions (40,38,34) on the upper side (22) of the substrate (16) are electrically isolated from one another, - wherein within the well region (24) and below the collector region (34) and laterally around it there is a well sub-region (32) of the second conductivity type, which is less doped than the well region (24) and which is from both the base Region (40) and from the emitter region (38) is spaced apart, - wherein the extension and / or doping of the well sub-region (32) defines the breakdown voltage, - wherein the collector region (34) forms a first connection (36) and - wherein the emitter region (38) is electrically connected to the base region (40) and both form a second connection (48). Electronic component according to Claim 1 , characterized in that the collector, emitter and base regions (40,38,34) are most heavily doped, that the well region (24) is weaker than the collector, emitter and base regions (40,38, 34) is doped, that the tub sub-region (32) is less doped than the tub region (24) and that the second substrate layer (20) of the substrate (16) has an electrical resistance that can be represented by a doping that is the same size as or is less than the doping of the well sub-region (32). Electronic component according to Claim 1 or 2 , characterized in that the first conductivity type is the p conductivity type and the second conductivity type is the n conductivity type or that the first conductivity type is the n conductivity type and the second conductivity type is the p conductivity type. Electronic component according to one of the Claims 1 to 3 , characterized in that a weakly doped additional well region (52) of the first conductivity type is formed within the well sub-region (32) and below the collector region (34) and laterally around it. Electronic component according to one of the Claims 1 to 4th , characterized in that the additional well region (52) is more weakly doped than the collector region (34) and / or that the additional well region (52) is doped as weakly or more weakly or more heavily than the partial well region (32). Electronic component according to one of the Claims 1 to 5 , characterized in that electrically insulating insulation regions are formed on the top (22) of the substrate (16) between the base, emitter and collector regions (40,38,34) which protrude into the well region (24), wherein the insulation areas adjoining the collector area (34) protrude into the tub sub-area (32) and, if present, into the additional tub area (52). Electronic component according to one of the Claims 1 to 6th , characterized in that the tub region (24) has a first depth (T1) and that the tub sub-region (32) outside the tub region (24) has a second depth (T2) which is smaller than the first depth (T1) and smaller is than the thickness of the second substrate layer (20). Electronic component according to one of the Claims 1 to 7th , characterized in that the extension of the tub sub-region (32) in its width and / or depth and / or the doping of the tub sub-region (32) defines the switching threshold from which, when a reverse voltage is applied between the first terminal (36) and the second terminal (48) a current flows in the tub region (24) and the tub sub-region (32) due to an avalanche breakdown. Electronic component according to one of the Claims 1 to 8th , characterized in that the first semiconductor material viewed independently of its doping and the second semiconductor material viewed regardless of its doping are the same or different. Electronic component with two definable breakdown voltages to protect electronic components and / or circuits from impairment of function due to overvoltages, with - A semiconducting substrate (16) having a top side (22) with a first substrate layer (18) which has epitaxially grown first semiconductor material which is lightly doped and of a first power type, and with a second layer arranged on the first substrate layer (18) Substrate layer (20) which has a second semiconductor material which is very weakly doped epitaxially grown on the first semiconductor material of the first substrate layer (18) and is of a second conduction type that is inverse to the first conduction type, the second substrate layer (20) having a contact with the first substrate layer ( 18) has connected lower end and an upper side facing away from this and forming the upper side (22) of the substrate (16), - A lightly doped well region (24) of the second conductivity type, which extends from the top (22) of the substrate (16) into the second substrate layer (20) and whose depth is less than the thickness of the second substrate layer (20), - A heavily doped base region (40) of the second conductivity type, arranged on the upper side (22) of the substrate (16) and extending into the well region (24), - Two heavily doped emitter regions (38) of the first conductivity type, arranged on the upper side (22) of the substrate (16) and extending into the well region (24) at a distance from the base region (40), between which the base region Area (40) is arranged, and - Two heavily doped collector regions formed on the top (22) of the substrate (16) and extending into the well region (24) at a distance from both the base region (40) and the emitter regions (38) (34) of the first conductivity type, between which the two emitter regions (38) and the base region (40) are arranged, - The base, emitter and collector regions (40,38,34) on the upper side (22) of the substrate (16) are electrically isolated from one another, - A well sub-area (32) of the second conductivity type being located within the well region (24) and below each collector region (34) as well as laterally around each of the collector regions (34), with both well sub-regions (32) being less doped than the tub area, - each well sub-region being spaced apart from both the base region and the emitter region adjacent to it, - wherein the one collector region forms a first connection (36) and the other collector region forms a second connection (48) and - The two emitter regions (38) and the base region (40) being electrically connected to one another. Electronic component according to Claim 10 , characterized in that the collector regions (34) and the base region (40) are most heavily doped, that the well region (24) is weaker than the collector, emitter and base regions (40,38,34) is doped so that the two well sub-regions (32) are equally weakly or differently weakly doped and each well sub-region (32) is less doped than each of the well regions (24) and that the second substrate layer (20) of the substrate (16) has an electrical resistance , which can be represented by a doping that is equal to or less than the doping of each of the well regions (24). Electronic component according to one of the Claims 10 or 11 , characterized in that the first conductivity type is the p conductivity type and the second conductivity type is the n conductivity type or that the first conductivity type is the n conductivity type and the second conductivity type is the p conductivity type Electronic component according to one of the Claims 10 to 12 , characterized in that a weakly doped additional well region (52) of the first conductivity type is formed within at least one of the well subregions (32) and below the relevant collector region (34) and laterally around it. Electronic component according to one of the Claims 10 to 13 , characterized in that a weakly doped additional well region (52) of the first conductivity type is formed within each well sub-region (32) and below the relevant collector region (34) and laterally around it, and that the doping of both additional well regions (52) is the same or different is weak. Electronic component according to Claim 13 or 14th , characterized in that at least one of the additional well regions (52) or each additional well region (52) is less doped than the respective collector region (34) which is arranged in the relevant additional well region (52). Electronic component according to one of the Claims 10 to 15th , characterized in that on the top (22) of the substrate (16) between the base, emitter and collector regions (40,38,34) electrically insulating insulation regions (41,42,44,46) are formed which protrude into the tub sub-region (32), the insulation regions (41, 42, 44, 46) adjoining the collector region (34) protruding into the tub sub-region (32) and, if present, into the additional tub region (52). Electronic component according to one of the Claims 10 to 16 , characterized in that each well region (24) has a first depth (T1) and that the well subregions (32) outside of the well region have a second depth (T2) which is smaller than the first depth (T1) and smaller than that Thickness of the second substrate layer (20). Electronic component according to one of the Claims 10 to 17th , characterized in that the two tub subareas (32) have the same or different depth. Electronic component according to one of the Claims 10 to 18th , characterized in that the extension of each well sub-area (32) in its width and / or depth and / or the doping of each well sub-area (32) define switching thresholds that are the same or different and from which on application of a first reverse voltage with a first polarity reversal or when a second reverse voltage is applied with a polarity inverse to the first polarity reversal between the first connection (36) and the second connection (48) in the tub subregions (32) and in the tub region (24) due to an avalanche breakdown, a current flows. Electronic component according to one of the Claims 10 to 19th , characterized in that the first semiconductor material viewed independently of its doping and the second semiconductor material viewed regardless of its doping are the same or different. Electronic component according to one of the Claims 10 to 20th , characterized in that the two emitter regions (38) are combined to form a common emitter region (38 '), that the common emitter region (38') is arranged between the two collector regions (34) and that the Base area (40) is arranged outside the area which is occupied on the upper side (22) of the substrate (16) by the arrangement of the common emitter area (38 ') and the two collector areas (34).

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