DE102010062448B4 - Process for the production of semiconductor structures from silicon carbide and silicon carbide semiconductors - Google Patents
Process for the production of semiconductor structures from silicon carbide and silicon carbide semiconductors Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 75
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 23
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 17
- 239000004065 semiconductor Substances 0.000 title claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 7
- 238000002513 implantation Methods 0.000 claims abstract description 53
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims abstract description 34
- 229920005591 polysilicon Polymers 0.000 claims abstract description 29
- 125000006850 spacer group Chemical group 0.000 claims abstract description 28
- 239000000758 substrate Substances 0.000 claims abstract description 28
- 238000005530 etching Methods 0.000 claims abstract description 21
- 230000003647 oxidation Effects 0.000 claims abstract description 14
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 14
- 238000000708 deep reactive-ion etching Methods 0.000 claims abstract description 13
- 230000000873 masking effect Effects 0.000 claims abstract description 11
- 238000000151 deposition Methods 0.000 claims abstract description 9
- 238000001312 dry etching Methods 0.000 claims abstract description 9
- 230000008021 deposition Effects 0.000 claims abstract description 7
- 230000007704 transition Effects 0.000 claims abstract description 6
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 4
- BLIQUJLAJXRXSG-UHFFFAOYSA-N 1-benzyl-3-(trifluoromethyl)pyrrolidin-1-ium-3-carboxylate Chemical compound C1C(C(=O)O)(C(F)(F)F)CCN1CC1=CC=CC=C1 BLIQUJLAJXRXSG-UHFFFAOYSA-N 0.000 claims abstract description 3
- JOHWNGGYGAVMGU-UHFFFAOYSA-N trifluorochlorine Chemical compound FCl(F)F JOHWNGGYGAVMGU-UHFFFAOYSA-N 0.000 claims abstract 2
- 238000004518 low pressure chemical vapour deposition Methods 0.000 claims description 5
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 6
- 239000010703 silicon Substances 0.000 description 5
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 4
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 4
- 229910052681 coesite Inorganic materials 0.000 description 3
- 229910052906 cristobalite Inorganic materials 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 238000005334 plasma enhanced chemical vapour deposition Methods 0.000 description 3
- 239000000377 silicon dioxide Substances 0.000 description 3
- 229910052682 stishovite Inorganic materials 0.000 description 3
- 229910052905 tridymite Inorganic materials 0.000 description 3
- 229920001817 Agar Polymers 0.000 description 2
- 238000001505 atmospheric-pressure chemical vapour deposition Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000002028 premature Effects 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 238000001039 wet etching Methods 0.000 description 2
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000007943 implant Substances 0.000 description 1
- 239000004922 lacquer Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- VPAYJEUHKVESSD-UHFFFAOYSA-N trifluoroiodomethane Chemical compound FC(F)(F)I VPAYJEUHKVESSD-UHFFFAOYSA-N 0.000 description 1
- 238000007704 wet chemistry method Methods 0.000 description 1
- IGELFKKMDLGCJO-UHFFFAOYSA-N xenon difluoride Chemical compound F[Xe]F IGELFKKMDLGCJO-UHFFFAOYSA-N 0.000 description 1
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Abstract
Ein Verfahren zur Herstellung von Halbleiterstrukturen aus Silizium-Carbid, das folgende Schritte aufweist:- Aufbringen einer Poly-Siliziumschicht (11) auf ein Substrat (10) aus Silizium-Carbid,- Maskierung der Poly-Siliziumschicht (11), wobei die Maske mindestens ein Fenster zur Schaffung eines Trenchs (12) sowie mindestens ein Fenster zur Schaffung eines Implantationsbereiches (14) aufweist,- Übertragen der Strukturen der Maskierung in die Poly-Siliziumschicht (11) durch einen DRIE-Trockenätzprozess, wobei zwischen Trench (12) und Implantationbereich (14) ein Spacer (13) aus Poly-Silizium gegeben ist,- Entfernung der Maskierung,- Ausbildung einer Oxidschicht (19) mittels thermischer Oxidation des beschichteten Substrates (10) bei einer Temperatur, die geringer ist als zur Oxidation von Silizium-Carbid notwendig,- Abscheidung einer SiO2-HTO-Schicht (22),- Implantation des Implantationsbereichs (14),- Öffnung der Oxidschicht (19) und der SiO2-HTO-Schicht (22)_am Übergang der Poly-Siliziumschicht (11) zum Implantationsbereich (14) mittels eines Trockenätzprozesses,- Entfernung des Spacers (13) durch einen plasmalosen Ätzprozess mittels Chlortrifluorid oder Xenondifluorid,- Entfernung der Restoxidhülle sowie des kompletten Oxids auf dem Substrat und der Poly-Siliziumschicht (11).A method for producing semiconductor structures from silicon carbide, comprising the steps of: - depositing a polysilicon layer (11) on a substrate (10) made of silicon carbide, - masking the polysilicon layer (11), the mask comprising at least has a window for creating a trench (12) and at least one window for creating an implantation area (14),- transferring the structures of the masking into the polysilicon layer (11) by a DRIE dry etching process, with between trench (12) and implantation area (14) there is a spacer (13) made of polysilicon, - removal of the masking, - formation of an oxide layer (19) by thermal oxidation of the coated substrate (10) at a temperature which is lower than for the oxidation of silicon carbide necessary, - deposition of a SiO2-HTO layer (22), - implantation of the implantation area (14), - opening of the oxide layer (19) and the SiO2-HTO layer (22)_at the transition of the polysilicon ium layer (11) to the implantation area (14) by means of a dry etching process, - removal of the spacer (13) by a plasma-free etching process using chlorine trifluoride or xenon difluoride, - removal of the residual oxide shell and the complete oxide on the substrate and the polysilicon layer (11).
Description
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von Halbleiterstrukturen aus Silizium-Carbid sowie verfahrensgemäß hergestellte Halbleiter.The present invention relates to a method for producing semiconductor structures from silicon carbide and semiconductors produced according to the method.
Stand der TechnikState of the art
Bei der Herstellung von Halbleiterbauelementen aus Silizium-Carbid (SiC), insbesondere von Transistoren und dort speziell von MOSFET's (metal oxide semiconductor field-effect transistors), werden an die laterale Kontrolle von Implantationsgebieten höchste Anforderungen gestellt. Die Kontrolle der Kanallänge ist beispielsweise bei den MOSFET's von entscheidender Bedeutung. Um diese Kanallänge reproduzierbar zu gewährleisten, wurden nach dem Stand der Technik verschiedene Verfahren vorgeschlagen und angewendet.In the production of semiconductor components from silicon carbide (SiC), in particular transistors and there specifically MOSFETs (metal oxide semiconductor field-effect transistors), the highest demands are placed on the lateral control of implantation regions. Controlling the channel length is of crucial importance for MOSFETs, for example. In order to ensure this channel length in a reproducible manner, various methods have been proposed and used according to the prior art.
Eine der erfolgreichsten und bei kleinen Kanallängen bevorzugte und etablierte Technologie ist die so genannte „Self Alignment“-Technik (selbstjustierender Prozess). Die Realisierung kann dabei prinzipiell mit zwei verschiedenen Techniken erfolgen, der so genannten Spacer-Technik oder auch Purdue-Technik sowie der Etch-Technik.One of the most successful technologies, which is preferred and established for small channel lengths, is the so-called "self-alignment" technique (self-adjusting process). In principle, this can be realized using two different techniques, the so-called spacer technique or Purdue technique and the etch technique.
Jede der Techniken hat gemein, dass sie die unterschiedliche Implantation von verschiedenen Bereichen mit nur einer Belichtungsebene und daher frei von Belichtungstoleranzen, das heißt selbstjustierend von zwei unterschiedlichen Belichtungen erlaubt.Each of the techniques has in common that they allow the different implantation of different areas with only one exposure level and therefore free of exposure tolerances, i.e. self-aligning of two different exposures.
Während die Spacer-Technik durch eine Positionierung eines so genannten Spacers nach der ersten Implantation den Bereich für die nächste Implantation gezielt verkleinert, wird mit der Etch-Technik der Implantationsbereich durch das gezielte Entfernen einer Maskierungsschicht der Bereich für die nachfolgende Implantation erweitert. Diese Technik wird beispielhaft in der
Zur Herstellung von Mikrostrukturen in Silizium ist das reaktive lonentiefenätzen (deep reactive ion etching, DRIE) bekannt, dies ist ein Trockenätzprozess, mit dem senkrecht zur Wafer-Oberfläche geätzt wird.Deep reactive ion etching (DRIE) is known for producing microstructures in silicon. This is a dry etching process that is used to etch perpendicularly to the wafer surface.
Offenbarung der ErfindungDisclosure of Invention
Erfindungsgemäß wird ein Verfahren zur Herstellung von Halbleiterstrukturen aus Silizium-Carbid zur Verfügung gestellt, mit dem eine präzise, homogene und reproduzierbare Strukturierung möglich ist. Dabei werden die Implantationsgebiete vorteilhafterweise nicht durch einen zeitgesteuerten Prozess, sondern durch die Festlegung des Designs definiert.According to the invention, a method for producing semiconductor structures from silicon carbide is made available, with which precise, homogeneous and reproducible structuring is possible. In this case, the implantation regions are advantageously not defined by a time-controlled process, but rather by defining the design.
Erfindungsgemäß werden zudem verfahrensgemäß hergestellte Halbleiter bereitgestellt.According to the invention, semiconductors produced according to the method are also provided.
Besonders vorteilhaft kann das erfindungsgemäße Verfahren eingesetzt werden, wenn sehr hohe Anforderungen an die Homogenität bei der Parallelschaltung von Einzeltransistoren gestellt werden. Bevorzugt wird das Verfahren für den Aufbau von vertikalen MOSFET-Bauteilen, bei denen das laterale Kanalgebiet durch den lateralen Überlapp eines Basisgebiets über ein Source-Gebiet definiert ist und die weitgehend homogen und von Wafer zu Wafer reproduzierbar hergestellt werden sollen.The method according to the invention can be used particularly advantageously when very high demands are placed on the homogeneity in the parallel connection of individual transistors. The method is preferred for the construction of vertical MOSFET components in which the lateral channel region is defined by the lateral overlap of a base region over a source region and which are to be manufactured largely homogeneously and reproducibly from wafer to wafer.
Das erfindungsgemäße Verfahren zur Herstellung von Halbleiterstrukturen aus Silizium-Carbid weist nachfolgend beschriebene Schritte auf, wobei auf die Darstellung von Reinigungsschritten und Standardprozessschritten verzichtet wird bzw. diese zusammengefasst werden, da diese dem Fachmann geläufig sind:
- - Aufbringen einer Poly-Siliziumschicht auf ein Substrat bzw. einen Wafer aus Silizium-Carbid (SiC).
- - Maskierung der Poly-Siliziumschicht, wobei die Maske mindestens ein Fenster zur Schaffung eines Grabens (Trenchs) sowie mindestens ein Fenster zur Schaffung eines Implantationsbereiches aufweist.
- - Übertragen der Strukturen der Maskierung in die Poly-Siliziumschicht durch einen DRIE-Trockenätzprozess (deep reactive ion etching), so dass zwischen Trench und Implantationsbereich ein definierter abgetrennter Bereich (Spacer) entsteht. Der Spacer weist bedingt durch den Trockenätzprozess einen zum Implantationsbereich weisenden Trenchrippel, eine charakteristische wellenförmige Wandstruktur, auf. Der Implantationsbereich kann oberflächlich leicht angeätzt sein kann. Da der Prozess eine hohe Selektivität von Silizium zu Silizium-Carbid (SiC) aufweist, liegt jedoch die durch das Ätzen erzeugte Stufe im Nanometerbereich.
- - Entfernung der Maskierung und gegebenenfalls Reinigung des Substrats
- - Thermische Oxidation des beschichteten Substrates bei einer Temperatur, die geringer ist als zur Oxidation von SiC notwendig. Vorzugsweise liegt die Temperatur im Bereich von 900 °C bis 1000 °C in Sauerstoff. Dabei schließt sich der Trench und die strukturierte Poly-Siliziumschicht wird mit einer Oxid-Schicht überzogen. Wesentlich bei diesem Schritt ist, dass sich bei ansonsten homogener Oxidierung an der Kante am Übergang der Poly-Siliziumschicht zum Trenchrippel eine nur unzureichend homogene Oxid-Schicht ausbildet. Im Gegensatz dazu ist der geschlossene Trench inaktiv, da dieser komplett verfüllt und abgedeckt ist. Der Implantationsbereich aus Silizium-Carbid verbleibt unbeschichtet.
- - Abscheidung einer HTO-Schicht (high temperature oxid) aus SiO2 zur Oxidverstärkung auf der Poly-Siliziumschicht und als Streuoxid für die Implantation. Vorzugsweise erfolgt die Abscheidung durch einen LPCVD-Prozess (low pressure chemical vapor deposition), es sind jedoch auch andere CVD-Techniken anwendbar wie PECVD (plasma enhanced chemical vapour deposition), SACVD (sub-atmospheric pressure chemical vapor deposition) und dergleichen. Der Vorteil der HTO-Schicht ist eine gute Spaltgängigkeit. Dadurch wird eine Dickenüberhöhung an Kanten vermieden und Ecken am Trench werden konform überdeckt Die Geometrie des Trenchrippels wird durch diese Schicht ebenfalls bedeckt, aber nicht in gleichem Maße wie eine planare, ebene Schicht.
- - Implantation des Implantationsbereichs je nach gewünschter Dotierung und erforderlichem Dotierprofil, so dass im Gegensatz zum übrigen Substrat im Implantationsbereich die gewünschten neuen Eigenschaften gegeben sind.
- - Öffnung der Oxidschicht an der Kante am Übergang der Poly-Siliziumschicht zum Trenchrippel durch einen Trockenätzprozess, vorzugsweise einen DRIE-Prozess, wobei an planaren Flächen eine homogene Ätzrate gegeben ist, während an Kanten eine erhöhte Ätzrate auftritt. Dadurch und bedingt durch eine geringere Oxiddicke an der genannten Kante führt das Ätzen zu einer vorzeitigen Abdünnung bis zur Spaltbildung im Oxid. Der Prozess wird gestoppt, nachdem sich ein Zugang zum Spacer gebildet hat. Alternativ kann auch ein Prozess eingesetzt werden, der am Fuß des Trenchrippels durch eine Taschenbildung einen Zugang zum Spacer schafft. In den anderen Bereichen verbleibt eine ausreichend dicke Oxidschicht zum Schutz des Siliziums.
- - Entfernung des Spacers durch einen plasmalosen Ätzprozess mittels Chlortrifluoid oder Xenondifluorid. Das Ätzen erfolgt über den zuvor geschaffenen Zugang zum Spacer und entfernt das Poly-Silizium des Spacers vollständig. Da der Ätzangriff am vollständig mit Oxid geschützten Trench und an intakten planaren mit Oxid geschützten Poly-Siliziumflächen nicht erfolgen kann, wird selektiv nur der Spacer entfernt. Auch ein nur unvollständig, nicht umlaufend geöffneter Trenchrippel stellt kein Problem dar, da auf Grund der Kapillarwirkung des CIF3-Ätzgases weite Unterätzweiten realisierbar sind. Auch ein Zusammenfallen der Oxidhülle stellt kein Problem dar. Vorteilhafterweise wird auch die dem Ätzgas ausgesetzte Oberfläche des Substrats hinsichtlich Rauigkeit und Kristallfehlern gleichzeitig mit dem Entfernen des Poly-Sililzium-Spacers verbessert. Vorteilhafterweise wird durch die hohe Selektivität des vorzugsweise verwendeten Ätzgases (CIF3) zur Opferschicht (Si) und der Passivierung (SiO2) ein Ätzstopp erreicht, der große Prozesstoleranzen erlaubt und gleichzeitig die im Design festgelegten engen Toleranzen ermöglicht.
- - Entfernung der Restoxidhülle sowie des kompletten Oxids, vorzugsweise mittels isotroper Nassätzung mit flusssäurehaltiger Ätzlösung. Nach Entfernung des kompletten Oxids ist die Kante des vorher mit Oxid geschützten Trenchs zur Begrenzung der nächsten Implantationsebene geworden.
- - Implantation der nächsten Implantationsebene
- - Application of a poly-silicon layer on a substrate or a wafer made of silicon carbide (SiC).
- - Masking the polysilicon layer, the mask having at least one window to create a trench (trench) and at least one window to create an implantation area.
- - Transferring the structures of the masking into the polysilicon layer by means of a DRIE dry etching process (deep reactive ion etching), so that a defined, separated area (spacer) is created between the trench and the implantation area. Due to the dry etching process, the spacer has a trench ripple, a characteristic wavy wall structure, pointing towards the implantation area. The surface of the implantation area can be slightly etched. However, since the process has a high selectivity from silicon to silicon carbide (SiC), the step created by etching is in the nanometer range.
- - Removal of the mask and, if necessary, cleaning of the substrate
- - Thermal oxidation of the coated substrate at a temperature lower than that necessary for the oxidation of SiC. Preferably the temperature is in the range of 900°C to 1000°C in oxygen. The trench closes and the structured polysilicon layer is coated with an oxide layer. What is essential in this step is that, with otherwise homogeneous oxidation, an insufficiently homogeneous oxide layer forms at the edge at the transition from the polysilicon layer to the trench ripple. In contrast, the closed trench is inactive because it is completely filled and covered. The silicon carbide implantation area remains uncoated.
- - Deposition of an HTO (high temperature oxide) layer of SiO2 for oxide reinforcement on the polysilicon layer and as scattering oxide for the implantation. The deposition preferably takes place by an LPCVD process (low-pressure chemical vapor deposition), but other CVD techniques can also be used, such as PECVD (plasma-enhanced chemical vapor deposition), SACVD (sub-atmospheric pressure chemical vapor deposition) and the like. The advantage of the HTO layer is good gap penetration. This avoids an increase in thickness at edges and corners on the trench are covered conformally. The geometry of the trench ripple is also covered by this layer, but not to the same extent as a planar, flat layer.
- - Implantation of the implantation area depending on the desired doping and the required doping profile, so that, in contrast to the rest of the substrate, the desired new properties are given in the implantation area.
- - Opening of the oxide layer at the edge at the transition from the polysilicon layer to the trench ripple by a dry etching process, preferably a DRIE process, with a homogeneous etching rate being given on planar surfaces, while an increased etching rate occurs on edges. Because of this and due to a lower oxide thickness at the mentioned edge, the etching leads to a premature thinning up to the formation of gaps in the oxide. The process is stopped after access to the spacer is established. Alternatively, a process can also be used that creates access to the spacer at the foot of the trench ripple by creating a pocket. A sufficiently thick oxide layer remains in the other areas to protect the silicon.
- - Removal of the spacer by a plasma-free etching process using chlorine trifluoid or xenon difluoride. The etching takes place via the previously created access to the spacer and completely removes the poly-silicon of the spacer. Since the etching attack cannot take place on the fully oxide-protected trench and on intact planar oxide-protected polysilicon surfaces, only the spacer is selectively removed. Even a trench ripple that is only incompletely open and not open around the circumference does not pose a problem, since large undercut widths can be realized due to the capillary effect of the CIF 3 etching gas. Collapse of the oxide shell is also not a problem. Advantageously, the surface of the substrate exposed to the etching gas is also improved in terms of roughness and crystal defects at the same time as the removal of the polysilicon spacer. Advantageously, the high selectivity of the etching gas (CIF 3 ) preferably used for the sacrificial layer (Si) and the passivation (SiO 2 ) achieves an etch stop that allows large process tolerances and at the same time allows the tight tolerances specified in the design.
- - Removal of the residual oxide shell and the complete oxide, preferably by means of isotropic wet etching with an etching solution containing hydrofluoric acid. After removing all the oxide, the edge of the previously oxide protected trench has become the boundary of the next implant level.
- - implantation of the next implantation level
Mit dieser erfindungsgemäßen Abfolge von Verfahrensschritten ist mittels einer Maskenebene ein selbstjustierendes Verfahren zweier Implantationsgebiete gegeben.With this sequence of method steps according to the invention, a self-aligning method of two implantation regions is provided by means of a mask level.
Der Vorteil des erfindungsgemäßen Verfahrens zu bekannten Technologien ist der Verzicht eines zeitgesteuerten Ätzprozesses durch Verwendung eines Prozesses mit Stoppschicht (Oxidhülle) und die Realisierung von großen als auch kleinen Kanallängen mit extrem hoher Genauigkeit im Anwendungsfall von FET-Bauteilen. Auch sehr geringe Kanallängen lassen sich vorteilhafterweise realisieren, wobei diese durch die Auflösungsgrenze bei der Maskierung bestimmt werden.The advantage of the method according to the invention over known technologies is that a time-controlled etching process is dispensed with by using a process with a stop layer (oxide shell) and the realization of both large and small channel lengths with extremely high accuracy when used with FET components. Even very short channel lengths can advantageously be implemented, these being determined by the resolution limit during the masking.
Nach einer bevorzugten Ausführungsform kann diese durch einen kontrollierten Trockenoxidationsprozess bis im Submikrometerbereich nachjustiert werden. Somit sind die Toleranzen bei den erfindungsgemäßen Halbleitern extrem klein, da etwaige anlagenbedingte Toleranzschwankungen wenn nötig nachträglich ausgeglichen werden können.According to a preferred embodiment, this can be readjusted down to the submicrometer range by a controlled dry oxidation process. The tolerances in the semiconductors according to the invention are therefore extremely small, since any plant-related tolerance fluctuations can be compensated for later if necessary.
Vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen angegeben und in der Beschreibung beschrieben.Advantageous developments of the invention are specified in the dependent claims and described in the description.
Figurenlistecharacter list
Ausführungsbeispiele der Erfindung werden anhand der Zeichnungen und der nachfolgenden Beschreibung näher erläutert. Es zeigen:
-
1 in einer geschnittenen Seitenansicht ein Substrat aus Silizium-Carbid, das teilweise mit einer Poly-Siliziumschicht beschichtet ist, -
2 in einer geschnittenen Seitenansicht das Substrat nach einer thermischen Oxidierung, -
3 in einer geschnittenen Seitenansicht ein Detail des Trenchrippels des Substrats, -
4 in einer geschnittenen Seitenansicht das Substrat mit einer HTO-Schicht und einer dotierten Implantationsschicht, -
5 in einer geschnittenen Detailansicht den Trenchrippel des Substrats, -
6 in einer geschnittenen Seitenansicht das Substrat nach einem Ätzprozess zur partiellen Ausdünnung der Oxidschichten, -
7 in einer geschnittenen Seitenansicht das Substrat nach Durchführung eines CIF3- Ätzprozesses, -
8 in einer geschnittenen Seitenansicht das Substrat nach Entfernung aller Oxidschichten, -
9 in einer geschnittenen Seitenansicht das Substrat mit einer Streuoxidschicht und einer zweiten Implantationsebene, und -
10 in einer geschnittenen Seitenansicht das Substrat mit verfahrensgemäß hergestellter Halbleiterstruktur.
-
1 a sectional side view of a silicon carbide substrate partially coated with a polysilicon layer, -
2 in a sectional side view the substrate after thermal oxidation, -
3 in a sectional side view a detail of the trench ripple of the substrate, -
4 in a sectional side view the substrate with an HTO layer and a doped implantation layer, -
5 the trench ripple of the substrate in a sectional detail view, -
6 in a sectional side view the substrate after an etching process for partial thinning of the oxide layers, -
7 in a sectional side view the substrate after carrying out a CIF 3 - etching process, -
8th in a sectional side view the substrate after removing all oxide layers, -
9 in a sectional side view, the substrate with a scattered oxide layer and a second implantation level, and -
10 in a sectional side view, the substrate with the semiconductor structure produced according to the method.
In
Diese nachfolgende Abscheidung ist in
In
In
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DE102010062448.9A DE102010062448B4 (en) | 2010-12-06 | 2010-12-06 | Process for the production of semiconductor structures from silicon carbide and silicon carbide semiconductors |
IT002187A ITMI20112187A1 (en) | 2010-12-06 | 2011-11-30 | PROCEDURE FOR THE PRODUCTION OF SILICON CARBIDE SEMICONDUCTOR STRUCTURES, AS WELL AS THE SILICON CARBIDE SEMICONDUCTOR |
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WO1999007011A1 (en) | 1997-07-31 | 1999-02-11 | Siemens Aktiengesellschaft | Method for configuring semiconductors with high precision, good homogeneity and reproducibility |
US20030052321A1 (en) | 2001-09-18 | 2003-03-20 | International Rectifier Corp. | Polysilicon fet built on silicon carbide diode substrate |
US20060237728A1 (en) | 2003-04-24 | 2006-10-26 | Sei-Hyung Ryu | Silicon carbide power devices with self-aligned source and well regions |
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WO1999007011A1 (en) | 1997-07-31 | 1999-02-11 | Siemens Aktiengesellschaft | Method for configuring semiconductors with high precision, good homogeneity and reproducibility |
US20030052321A1 (en) | 2001-09-18 | 2003-03-20 | International Rectifier Corp. | Polysilicon fet built on silicon carbide diode substrate |
US20060237728A1 (en) | 2003-04-24 | 2006-10-26 | Sei-Hyung Ryu | Silicon carbide power devices with self-aligned source and well regions |
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