EP1547135A1 - Semi-conductor dielectric component with a praseodymium oxide dielectric - Google Patents
Semi-conductor dielectric component with a praseodymium oxide dielectricInfo
- Publication number
- EP1547135A1 EP1547135A1 EP03769314A EP03769314A EP1547135A1 EP 1547135 A1 EP1547135 A1 EP 1547135A1 EP 03769314 A EP03769314 A EP 03769314A EP 03769314 A EP03769314 A EP 03769314A EP 1547135 A1 EP1547135 A1 EP 1547135A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- layer
- silicon
- oxide layer
- praseodymium
- mixed oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- MMKQUGHLEMYQSG-UHFFFAOYSA-N oxygen(2-);praseodymium(3+) Chemical compound [O-2].[O-2].[O-2].[Pr+3].[Pr+3] MMKQUGHLEMYQSG-UHFFFAOYSA-N 0.000 title claims abstract description 32
- 229910003447 praseodymium oxide Inorganic materials 0.000 title claims abstract description 32
- 239000004065 semiconductor Substances 0.000 title claims abstract description 20
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 42
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 42
- 239000010703 silicon Substances 0.000 claims abstract description 42
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 22
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 22
- 239000001301 oxygen Substances 0.000 claims abstract description 22
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 15
- 229910052777 Praseodymium Inorganic materials 0.000 claims abstract description 14
- PUDIUYLPXJFUGB-UHFFFAOYSA-N praseodymium atom Chemical compound [Pr] PUDIUYLPXJFUGB-UHFFFAOYSA-N 0.000 claims abstract description 13
- 238000004519 manufacturing process Methods 0.000 claims abstract description 5
- 238000000151 deposition Methods 0.000 claims description 26
- 239000000758 substrate Substances 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 12
- 230000008021 deposition Effects 0.000 claims description 9
- 239000007789 gas Substances 0.000 claims description 8
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 claims description 5
- 239000000956 alloy Substances 0.000 claims description 5
- 235000012239 silicon dioxide Nutrition 0.000 claims description 5
- 239000000377 silicon dioxide Substances 0.000 claims description 5
- 229910000577 Silicon-germanium Inorganic materials 0.000 claims description 4
- LEVVHYCKPQWKOP-UHFFFAOYSA-N [Si].[Ge] Chemical compound [Si].[Ge] LEVVHYCKPQWKOP-UHFFFAOYSA-N 0.000 claims description 4
- 239000007858 starting material Substances 0.000 claims description 4
- 238000005229 chemical vapour deposition Methods 0.000 claims description 3
- 229910052681 coesite Inorganic materials 0.000 claims description 2
- 229910052906 cristobalite Inorganic materials 0.000 claims description 2
- 229910052682 stishovite Inorganic materials 0.000 claims description 2
- 229910052905 tridymite Inorganic materials 0.000 claims description 2
- 239000002800 charge carrier Substances 0.000 abstract description 7
- 229910052814 silicon oxide Inorganic materials 0.000 abstract description 5
- 239000010410 layer Substances 0.000 description 72
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Inorganic materials [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 21
- 229910004298 SiO 2 Inorganic materials 0.000 description 17
- 238000010587 phase diagram Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 6
- 229910018557 Si O Inorganic materials 0.000 description 5
- 239000000203 mixture Substances 0.000 description 4
- 239000003989 dielectric material Substances 0.000 description 3
- 238000001451 molecular beam epitaxy Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 206010010144 Completed suicide Diseases 0.000 description 2
- WOSBVGOZEYQLLK-UHFFFAOYSA-N [Si].[O].[Pr] Chemical compound [Si].[O].[Pr] WOSBVGOZEYQLLK-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000001420 photoelectron spectroscopy Methods 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- -1 praseodymium ions Chemical class 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000005469 synchrotron radiation Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
- H01L21/28008—Making conductor-insulator-semiconductor electrodes
- H01L21/28017—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon
- H01L21/28158—Making the insulator
- H01L21/28167—Making the insulator on single crystalline silicon, e.g. using a liquid, i.e. chemical oxidation
- H01L21/28194—Making the insulator on single crystalline silicon, e.g. using a liquid, i.e. chemical oxidation by deposition, e.g. evaporation, ALD, CVD, sputtering, laser deposition
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/49—Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET
- H01L29/51—Insulating materials associated therewith
- H01L29/511—Insulating materials associated therewith with a compositional variation, e.g. multilayer structures
- H01L29/513—Insulating materials associated therewith with a compositional variation, e.g. multilayer structures the variation being perpendicular to the channel plane
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/49—Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET
- H01L29/51—Insulating materials associated therewith
- H01L29/517—Insulating materials associated therewith the insulating material comprising a metallic compound, e.g. metal oxide, metal silicate
Definitions
- the invention relates to a semiconductor component with a silicon-containing layer and a praseodymium oxide layer.
- the invention further relates to a method for producing such an electronic component.
- Pr 2 O 3 layers on Si (001) substrates are particularly suitable for replacing the traditional gate dielectric material Si0 2 in sub-0.1 ⁇ m CMOS technology.
- an ultra-thin SiO 2 layer between the Si substrate and an alternative dielectric material is necessary in order to adapt bonds and charges to one another and to reduce mechanical stresses and in this way to achieve high charge carrier mobility.
- such a thin SiO 2 intermediate layer reduces the dielectric effectiveness of the substitute material. If we assume that the thickness t h ig h .
- the technical problem on which the invention is based consists in specifying a semiconductor component of the type mentioned at the outset with a sufficiently high capacity and charge carrier mobility, even with particularly small dimensions. Another object of the invention is to provide a method for producing such an electronic component.
- the problem is solved by a semiconductor component with a silicon-containing layer and a praseodymium oxide layer, in which a mixed oxide layer containing silicon, praseodymium and oxygen is arranged between the silicon layer and the praseodymium oxide layer and has a layer thickness of less than 5 nanometers.
- the invention is based on the knowledge that a mixed oxide containing silicon, praseodymium and oxygen is suitable, the advantageous properties of the previously customary SiO 2 / Si (001) interface with those of the alternative dielectric praseodymium oxide (for example in the form Pr 2 0 3 ) to combine.
- the mixed oxide which is also referred to below as praseodymium silicate, has a greater dielectric constant than silicon oxide. Assuming that the mixed oxide layer has the same thickness as an otherwise necessary silicon oxide intermediate layer between the silicon-containing substrate and the praseodymium oxide, the minimum achievable equivalent oxide thickness is reduced according to equation (3) by a factor which corresponds to the ratio of the dielectric constant of praseodymium silicate and corresponds to silicon oxide. According to the current state of knowledge, the mixed oxide layer brings about a high mobility of the charge carriers in the component according to the invention in that there are Si-O bonds and no Si-Pr bonds at the interface with the silicon-containing layer. The Si-O bonds bring about electrical properties as are known from the SiO 2 / Si (001) interface.
- the mixed oxide layer according to the invention it is therefore possible on the one hand to ensure a very high interface quality and on the other hand to ensure a sufficiently high capacity. A transition from the silicon-containing substrate to the dielectric is achieved, which has all the required properties.
- the thickness of the mixed oxide layer influences the capacitance of a capacitor structure which comprises the silicon-containing layer and the praseodymium oxide layer in a semiconductor component according to the invention.
- the layer thickness is a maximum of 5 nm.
- the mixed oxide layer has a layer thickness of at most 3 nm.
- the mixed oxide layer is a pseudobinary, non-stoichiometric alloy of the type (Pr 2 0 3 ) x (SiO 2 ) 1-x or a silicate of this type.
- the value of x has been found to depend, among other things, on the layer thickness. This means that the coefficients x differ for components with different thicknesses of the mixed oxide layer.
- the coefficient x increases with the layer thickness.
- a detailed analysis of the composition of the mixed oxide, characterized by x, has shown that in the layer thickness range up to 3 nm the value x increases with the thickness from 0.3 to 1.
- the coefficient x increases between the silicon-containing layer and the praseodymium oxide layer. In this embodiment, the coefficient x increases within the mixed oxide layer.
- the silicon-containing layer consists of doped or undoped silicon.
- a doped or undoped silicon-germanium alloy can also be provided in the silicon-containing layer. If a silicon germanium alloy is used, nitrogen can also be incorporated into the silicon-containing layer in order to achieve a high-quality interface.
- the silicon-containing layer preferably has a (001) orientation at the interface with the mixed oxide layer. A particularly high interface quality is achieved in this way.
- the component according to the invention can preferably be used in particular in the form of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or in the form of a memory component in a RAM component (Random Access Memory) such as a dynamic ROM (DROM).
- MOSFET Metal Oxide Semiconductor Field Effect Transistor
- RAM component Random Access Memory
- DROM dynamic ROM
- the object is achieved by a production process for an electronic component with a step of depositing a praseodymium oxide layer on a silicon-containing layer, in which, before the aforementioned deposition step, a step of depositing a mixed oxide layer containing silicon, praseodymium and oxygen at a substrate temperature of less than 700 ° C takes place.
- the method according to the invention is based on the knowledge that the problem on which it is based can be solved if the alternative dielectric material praseodymium oxide Pr 2 0 3 can be grown on Si (001) in such a way that no SiO 2 intermediate layer is formed and also such a layer is not necessary in order to obtain a sufficiently high charge carrier mobility.
- This mixed oxide layer contains silicon, praseodymium and oxygen. It is of great importance for the interface quality and thus for the mobility of the charge carriers that no suicides are formed in the semiconductor component according to the invention at the interface with the substrate.
- the fact that praseodymium ions on the surface of the silicon-containing substrate material are subject to repulsive forces in the temperature range up to 800 ° C. is used here in an inventive manner, so that there are Si-O bonds and not Si-Pr bonds. This means that no suicides are formed at the interface with the substrate.
- the Si-O bonds that form instead at the interface result in particularly good electrical properties, as are known from the SiO 2 / Si (001) interface. Accordingly, there is a chemically reactive interface consisting of a mixed Si-Pr oxide of the form (Pr 2 O 3 ) x (SiO 2 ) 1-x , which is typically not stoichiometrically composed.
- the upper temperature limit of 700 ° C. specified according to the invention prevents decomposition of structural elements of the resulting component, in particular the mixed oxide layer itself.
- the steps of depositing a mixed oxide layer and depositing a praseodymium oxide layer preferably take the form of deposition from the gas phase. In this way, a particularly controlled growth of these layers is achieved.
- the deposition steps mentioned can be carried out by means of molecular beam deposition (molecular beam epitaxy, Molecular Beam Epitaxy, MBE) or by means of chemical vapor deposition (Chemical Vapor Deposition, CVD).
- the step of depositing the mixed oxide layer takes place in an oxygen-containing gas atmosphere. As will be explained in more detail below with reference to FIG. 1, it has been shown that the presence of oxygen in the gas atmosphere of the growth chamber is of great importance for the control of the layer composition.
- silicon monoxide SiO is formed instead of silicon dioxide SiO 2 .
- the composition, ie the stoichiometric coefficient x of the silicate (Pr 2 0 3 ) x (SiO 2 ) 1-x can be controlled with the aid of the oxygen supply. An excess of oxygen is of great importance for the formation of the Si-O bonds in the area due to the high reactivity of silicon from the silicon-containing layer and oxygen.
- An oxygen-containing gas atmosphere is also advantageous for the deposition of the praseodymium oxide layer.
- a material is used as a starting material for the step of depositing the mixed oxide layer, which contains praseodymium oxide in the form Pr 6 O ⁇ or even consists entirely of it.
- the reduction of praseodymium oxide Pr 6 On in the growth chamber ensures an oxygen partial pressure with which the layer growth takes place in the desired manner. With the aid of the temperature, the oxygen content of the gas atmosphere can be controlled in this embodiment.
- the step of depositing the mixed oxide layer preferably takes place at a substrate temperature of less than 680 ° C., in particular between 600 ° C. and 650 ° C. In this temperature range, in particular when using Pr ⁇ O-n as the starting material, a sufficient supply of oxygen can be ensured, which leads to the formation of the mixed oxide (Pr 2 0 3 ) x (SiO2) 1-x .
- FIG. 1 shows a ternary phase diagram for the system praseodymium-oxygen-silicon
- Figure 2 shows an embodiment of a semiconductor device according to the invention.
- Figure 1 shows a ternary phase diagram for the praseodymium-oxygen-silicon system. This phase diagram was determined experimentally in the context of research work in connection with the present invention.
- the phase diagram has three coordinate axes 10, 12 and 14, which are arranged in the form of an equilateral triangle.
- the corner points of the equilateral triangle are assigned the elements praseodymium, oxygen and silicon.
- the concentration of these elements corresponds to the value 1.
- the concentration of the respective element drops to the value zero.
- phase diagram With a silicon content of 0.5, silicon monoxide SiO is present. This point of the phase diagram is identified by reference number 16. With a silicon content of 0.33, silicon dioxide SiO 2 is present. This point of the phase diagram is identified by the reference symbol 18.
- the phase contains only praseodymium and oxygen and no silicon. The point 20 is shown, at which praseodymium oxide is in the form Pr 2 O 3 .
- Various experimentally determined phases of the mixed oxide within the triangle formed by the three coordinate axes 10, 12 and 14 are shown in the form of squares. The experimental values were determined with the aid of photoelectron spectroscopy using samples grown in the temperature range from 600 to 650 ° C.
- the samples were excited with synchrotron radiation and the energy of the electrons emerging from the sample was recorded and analyzed. It can be seen that the phases determined, depending on the oxygen content, lie on a quasi-binary cut line 22, which represents a mixed phase of praseodymium oxide Pr 2 O and silicon monoxide SiO, or on a quasi-binary cut line 24, which is a mixed phase of praseodymium oxide Pr 2 0 3 and Silicon dioxide Si0 2 represents.
- a (Pr 2 0 3 ) x (SiO 2 ) 1-x thortveitite structure was determined at a point 25 at which the intersection line 24 intersects the perpendicular bisector of the triangular phase diagram leading from the vertex to the base. At this Point 25 of the phase diagram shows that the proportion of silicon and praseodymium in the mixed oxide is the same.
- phase diagram in FIG. 1 accordingly shows that it has been possible to produce a praseodymium silicate or a pseudobinary, non-stoichiometric alloy (Pr 2 0 3 ) x (SiO 2 ) 1-x with an adjustable proportion x of the praseodymium oxide Pr 2 0 3 .
- FIG. 2 shows a section of an exemplary embodiment of a semiconductor component 30 according to the invention with a silicon substrate 32 and an adjacent mixed oxide layer 34.
- the substrate At an interface 36 between the silicon substrate 32 and the mixed oxide layer 34, the substrate has a (001) surface.
- the mixed oxide layer is a (Pr 2 0 3 ) x (SiO 2 ) 1-x layer in which the coefficient x has a value of 0.3 at the interface 36 and at an interface 38 to an adjacent praseodymium oxide layer (Pr 2 0 3 ) 40 has a value of 1.
- a polysilicon layer 42 is arranged above the praseodymium oxide layer 40.
- the inner structure of the substrate 32 is not shown here.
- the component 30, which is also shown here only in a section, can be, for example, a MOSFET or a memory element of a DROM memory.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Computer Hardware Design (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Ceramic Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Formation Of Insulating Films (AREA)
- Insulated Gate Type Field-Effect Transistor (AREA)
Abstract
The invention relates to a semi-conductor component having a layer containing silicon and a praseodymium oxide layer, whereon a mixed oxide layer containing silicon, praseodymium and oxygen is arranged between the silicon layer and the praseodymium oxide layer. The layer has a maximum thickness of 5 nanometers. The invention also relates to a method for producing one such semi-conductor component. With the aid of the mixed oxide layer, which contains a silicon oxide intermediate layer, the capacity of the component can be improved in relation to components known per se. High charge carrier movement is also obtained without the need for a silicon oxide intermediate layer.
Description
Halbleiterbauelement mit Praseodymoxid-Dielektrikum Semiconductor device with praseodymium oxide dielectric
Die Erfindung betrifft ein Halbleiterbauelement mit einer siliziumhaltigen Schicht und einer Praseodymoxidschicht. Weiterhin betrifft die Erfindung ein Verfahren zur Herstellung eines solchen elektronischen Bauelementes.The invention relates to a semiconductor component with a silicon-containing layer and a praseodymium oxide layer. The invention further relates to a method for producing such an electronic component.
Pr2O3-Schichten auf Si(001)-Substraten sind wegen ihrer vergleichsweise gro- ßen Dielektrizitätskonstanten (k « 30) besonders geeignet, das traditionelle gatedielektrische Material Si02 in der Sub-0,1 μm-CMOS-Technologie zu ersetzen. Es wird jedoch allgemein davon ausgegangen, dass eine ultradünne Si02-Schicht zwischen dem Si-Substrat und einem alternativen dielektrischen Material notwendig ist, um Bindungen und Ladungen aneinander anzupassen und mechanische Spannungen abzubauen und auf diese Weise eine hohe Ladungsträgerbeweglichkeit zu erzielen.
Wie folgende Betrachtung zeigt, verringert eine solche dünne SiO2- Zwischenschicht die dielektrische Wirksamkeit des Ersatzmaterials. Wenn wir davon ausgehen, dass die Dicke thigh./c des alternativen Dielektrikums dieselbe Kapazität bewirken soll wie eine Si02-Schicht mit der äquivalenten Dicke teq, ergibt sich ' -k = (kh\ -k I /fsio2) teq , (1 ) worin kSιo2 die Dielektrizitätskonstante des SiO2 ist. Da die SiO2-Zwischen- schicht eine in Reihe mit dem alternativen Dielektrikum geschaltete zweite Kapazität CSio2 darstellt, lässt sich die resultierende Kapazität wie folgt be- rechnen:Because of their comparatively large dielectric constants (k «30), Pr 2 O 3 layers on Si (001) substrates are particularly suitable for replacing the traditional gate dielectric material Si0 2 in sub-0.1 μm CMOS technology. However, it is generally assumed that an ultra-thin SiO 2 layer between the Si substrate and an alternative dielectric material is necessary in order to adapt bonds and charges to one another and to reduce mechanical stresses and in this way to achieve high charge carrier mobility. As the following observation shows, such a thin SiO 2 intermediate layer reduces the dielectric effectiveness of the substitute material. If we assume that the thickness t h ig h . / c of the alternative dielectric is to have the same capacitance as an Si0 2 layer with the equivalent thickness t eq , the result is' -k = (kh \ -k I / fsio 2 ) t eq , (1) where k S ιo 2 Dielectric constant of the SiO 2 is. Since the SiO 2 interlayer represents a second capacitance C S io 2 connected in series with the alternative dielectric, the resulting capacitance can be calculated as follows:
1 /Cres = 1 /Chigh-Λ + 1 /CSio2 , (2) wobei Chigh-/( die Kapazität der dielektrischen Schicht ist. Unter Verwendung von (1) erhält man dann für die äquivalente Dicke des Schichtsystems eq, bestehend aus einer dünnen Si02-Schicht tSio2 und der dielektrischen Schicht t igh-fc , t eq = tsiQ2 + (/fsi02 / iigh-/-) thigh-fr > (3)1 / Cres = 1 / Chigh-Λ + 1 / C S io 2 , (2) where C h ig h - / (is the capacitance of the dielectric layer. Using (1) one then obtains for the equivalent thickness of the layer system eq , consisting of a thin Si0 2 layer t S io 2 and the dielectric layer t igh-fc, t eq = tsiQ2 + (/ fsi02 / iigh - / -) thigh-fr> (3)
Aus (3) folgt unmittelbar, dass die minimal erreichbare äquivalente Oxiddicke ts eq niemals kleiner sein kann als die Dicke tSro2 der SiO2-Schicht. Deshalb ist die mit dem Einsatz eines Materials mit großer Dielektrizitätskonstante ange- strebte Zunahme der Kapazität gefährdet.It immediately follows from (3) that the minimum achievable equivalent oxide thickness t s eq can never be smaller than the thickness t S ro 2 of the SiO 2 layer. Therefore, the increase in capacitance aimed at using a material with a large dielectric constant is at risk.
Während eine sehr große Kapazität der Schicht bei extrem geringen Leckströmen wesentlich ist für die Anwendung des Materials in dynamischen RAMs (DRAMs), sind sehr hohe Interfacequalität und Ladungsträgerbeweglichkeit im Kanal maßgeblich für den Einsatz des Materials in MOSFETs. Das der Erfindung zu Grunde liegende technische Problem besteht darin, ein Halbleiterbauelement der eingangs genannten Art mit ausreichend hoher Kapazität und Ladungsträgerbeweglichkeit auch bei besonders geringen Ausmaßen anzugeben. Eine weitere Aufgabe der Erfindung ist es, ein Verfahren zur Herstellung eines solchen elektronischen Bauelements anzugeben. Hinsichtlich des Halbleiterbauelements wird das Problem gelöst durch ein Halbleiterbauelement mit einer siliziumhaltigen Schicht und einer Praseodym-
oxidschicht, bei dem zwischen der Siliziumschicht und der Praseodymoxidschicht eine Mischoxidschicht enthaltend Silizium, Praseodym und Sauerstoff angeordnet ist, die eine Schichtdicke von weniger als 5 Nanometern aufweist.While a very large capacitance of the layer with extremely low leakage currents is essential for the use of the material in dynamic RAMs (DRAMs), very high interface quality and charge carrier mobility in the channel are decisive for the use of the material in MOSFETs. The technical problem on which the invention is based consists in specifying a semiconductor component of the type mentioned at the outset with a sufficiently high capacity and charge carrier mobility, even with particularly small dimensions. Another object of the invention is to provide a method for producing such an electronic component. With regard to the semiconductor component, the problem is solved by a semiconductor component with a silicon-containing layer and a praseodymium oxide layer, in which a mixed oxide layer containing silicon, praseodymium and oxygen is arranged between the silicon layer and the praseodymium oxide layer and has a layer thickness of less than 5 nanometers.
Die Erfindung beruht auf der Erkenntnis, dass ein Mischoxid enthaltend Silizi- um, Praseodym und Sauerstoff geeignet ist, die vorteilhaften Eigenschaften der bisher üblichen SiO2/Si(001)-Grenzfläche mit denen des alternativen Dielektrikums Praseodymoxid (beispielsweise in der Form Pr203) zu kombinieren.The invention is based on the knowledge that a mixed oxide containing silicon, praseodymium and oxygen is suitable, the advantageous properties of the previously customary SiO 2 / Si (001) interface with those of the alternative dielectric praseodymium oxide (for example in the form Pr 2 0 3 ) to combine.
Das Mischoxid, das im folgenden auch als Praseodymsilikat bezeichnet wird, hat im Vergleich zu Siliziumoxid eine größere Dielektrizitätskonstante. Unter der Annahme, dass die Mischoxidschicht die gleiche Dicke besitzt, wie eine sonst notwendige Siliziumoxid-Zwischenschicht zwischen dem siliziumhaltigen Substrat und dem Praseodymoxid, verringert sich nach Gleichung (3) die minimal erreichbare äquivalente Oxiddicke um einen Faktor, der dem Verhältnis der Dielektrizitätskonstanten von Praseodymsilikat und Siliziumoxid entspricht. Die Mischoxidschicht bewirkt eine hohe Ladungsträgerbeweglichkeit bei dem erfindungsgemäßen Bauelement nach derzeitigem Kenntnisstand dadurch, dass an der Grenzfläche zur siliziumhaltigen Schicht Si-O-Bindungen und keine Si-Pr-Bindungen bestehen. Die Si-O Bindungen bewirken elektrische Eigenschaften, wie sie von der SiO2/Si(001)-Grenzfläche her bekannt sind. Mit Hilfe der erfindungsgemäßen Mischoxidschicht gelingt es demnach, einerseits eine sehr hohe Grenzflächenqualität und andererseits eine ausreichend hohe Kapazität zu gewährleisten. Es wird ein Übergang vom siliziumhaltigen Substrat zum Dielektrikum erzielt, der alle geforderten Eigenschaften aufweist.The mixed oxide, which is also referred to below as praseodymium silicate, has a greater dielectric constant than silicon oxide. Assuming that the mixed oxide layer has the same thickness as an otherwise necessary silicon oxide intermediate layer between the silicon-containing substrate and the praseodymium oxide, the minimum achievable equivalent oxide thickness is reduced according to equation (3) by a factor which corresponds to the ratio of the dielectric constant of praseodymium silicate and corresponds to silicon oxide. According to the current state of knowledge, the mixed oxide layer brings about a high mobility of the charge carriers in the component according to the invention in that there are Si-O bonds and no Si-Pr bonds at the interface with the silicon-containing layer. The Si-O bonds bring about electrical properties as are known from the SiO 2 / Si (001) interface. With the help of the mixed oxide layer according to the invention, it is therefore possible on the one hand to ensure a very high interface quality and on the other hand to ensure a sufficiently high capacity. A transition from the silicon-containing substrate to the dielectric is achieved, which has all the required properties.
Die Dicke der Mischoxidschicht beeinflusst nach dem zuvor gesagten die Ka- pazität einer Kondensatorstruktur, die die siliziumhaltige Schicht und die Praseodymoxidschicht in einem erfindungsgemäßen Halbleiterbauelement um- fasst. Erfindungsgemäß beträgt die Schichtdicke maximal 5 nm. Je höher der für ein erfindungsgemäßes Bauelement angestrebte Wert der Kapazität ist, desto geringer sollte die Schichtdicke der Mischoxidschicht gewählt werden. Daher werden meist geringe Schichtdicken der Mischoxidschicht bevorzugt. In einer Ausführungsform der Erfindung weist die Mischoxidschicht eine Schichtdicke maximal 3 nm auf.
Bei einer derzeit besonders bevorzugten Ausführungsform der Erfindung ist die Mischoxidschicht eine pseudobinäre, nicht stöchiometrische Legierung des Typs (Pr203)x(SiO2)1-x oder ein Silikat dieses Typs.According to the above, the thickness of the mixed oxide layer influences the capacitance of a capacitor structure which comprises the silicon-containing layer and the praseodymium oxide layer in a semiconductor component according to the invention. According to the invention, the layer thickness is a maximum of 5 nm. The higher the value of the capacitance aimed for for a component according to the invention, the smaller the layer thickness of the mixed oxide layer should be. Therefore, thin layers of the mixed oxide layer are usually preferred. In one embodiment of the invention, the mixed oxide layer has a layer thickness of at most 3 nm. In a currently particularly preferred embodiment of the invention, the mixed oxide layer is a pseudobinary, non-stoichiometric alloy of the type (Pr 2 0 3 ) x (SiO 2 ) 1-x or a silicate of this type.
Der Wert von x hat sich als unter anderem von der Schichtdicke abhängig herausgestellt. Das heißt, bei Bauelementen mit unterschiedlichen Dicken der Mischoxidschicht unterscheiden sich die Koeffizienten x. Der Koeffizient x nimmt mit der Schichtdicke zu. Eine eingehende Analyse der Zusammensetzung des Mischoxids, gekennzeichnet durch x, hat ergeben, dass im Schichtdickenbereich bis 3 nm der Wert x von 0,3 bis auf 1 mit der Dicke anwächst. Bei einer weiteren Ausführungsform der Erfindung steigt der Koeffizient x zwischen der siliziumhaltigen Schicht und der Praseodymoxidschicht an. Bei diesem Ausführungsbeispiel nimmt der Koeffizient x innerhalb der Mischoxidschicht zu.The value of x has been found to depend, among other things, on the layer thickness. This means that the coefficients x differ for components with different thicknesses of the mixed oxide layer. The coefficient x increases with the layer thickness. A detailed analysis of the composition of the mixed oxide, characterized by x, has shown that in the layer thickness range up to 3 nm the value x increases with the thickness from 0.3 to 1. In a further embodiment of the invention, the coefficient x increases between the silicon-containing layer and the praseodymium oxide layer. In this embodiment, the coefficient x increases within the mixed oxide layer.
Die siliziumhaltige Schicht besteht in einer bevorzugten Ausführungsform aus dotiertem oder undotiertem Silizium. Es kann jedoch auch eine dotierte oder undotierte Silizium-Germanium-Legierung in der siliziumhaltigen Schicht vorgesehen sein. Wird eine Silizium-Germanium-Legierung verwendet, kann zusätzlich Stickstoff in die siliziumhaltige Schicht eingebaut werden, um eine Grenzfläche hoher Qualität zu erzielen. Dabei hat die siliziumhaltige Schicht an der Grenzfläche zur Mischoxidschicht vorzugsweise eine (001)-Orientierung. Auf diese Weise wird eine besonders hohe Grenzflächenqualität erzielt.In a preferred embodiment, the silicon-containing layer consists of doped or undoped silicon. However, a doped or undoped silicon-germanium alloy can also be provided in the silicon-containing layer. If a silicon germanium alloy is used, nitrogen can also be incorporated into the silicon-containing layer in order to achieve a high-quality interface. The silicon-containing layer preferably has a (001) orientation at the interface with the mixed oxide layer. A particularly high interface quality is achieved in this way.
Das erfindungsgemäße Bauelement kann vorzugsweise insbesondere in Form eines MOSFETs (Metal Oxide Semiconductor Field Effect Transistor) oder in Form eines Speicherbauelements in einem RAM-Baustein (Random Access Memory) wie einem dynamischen ROM (DROM) Anwendung finden.The component according to the invention can preferably be used in particular in the form of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) or in the form of a memory component in a RAM component (Random Access Memory) such as a dynamic ROM (DROM).
Hinsichtlich ihres Verfahrensaspektes wird die Aufgabe gelöst durch ein Herstellungsverfahren für ein elektronisches Bauelement mit einem Schritt des Abscheidens einer Praseodymoxidschicht auf einer siliziumhaltigen Schicht, bei dem vor dem genannten Abscheideschritt ein Schritt des Abscheidens einer Mischoxidschicht enthaltend Silizium, Praseodym und Sauerstoff bei einer Substrattemperatur von weniger als 700°C erfolgt.
Das erfindungsgemäße Verfahren beruht auf der Erkenntnis, dass das ihm zu Grunde liegende Problem zu lösen ist, wenn es gelingt, das alternative dielektrische Material Praseodymoxid Pr203 so auf Si(001) zu wachsen, dass keine Si02-Zwischenschicht entsteht und auch eine solche Schicht nicht not- wendig ist, um eine ausreichend hohe Ladungsträgerbeweglichkeit zu erhalten.With regard to its process aspect, the object is achieved by a production process for an electronic component with a step of depositing a praseodymium oxide layer on a silicon-containing layer, in which, before the aforementioned deposition step, a step of depositing a mixed oxide layer containing silicon, praseodymium and oxygen at a substrate temperature of less than 700 ° C takes place. The method according to the invention is based on the knowledge that the problem on which it is based can be solved if the alternative dielectric material praseodymium oxide Pr 2 0 3 can be grown on Si (001) in such a way that no SiO 2 intermediate layer is formed and also such a layer is not necessary in order to obtain a sufficiently high charge carrier mobility.
Dies gelingt, indem eine Mischoxidschicht auf der Silizium enthaltenden Schicht aufgewachsen wird. Diese Mischoxidschicht enthält Silizium, Praseodym und Sauerstoff. Von großer Bedeutung für die Grenzflächenqualität und damit für die Ladungsträgerbeweglichkeit ist es, dass bei dem erfindungsgemäßen Halbleiterbauelement an der Grenzfläche zum Substrat keine Suizide gebildet werden. Hier wird in erfinderischer Weise die Tatsache genutzt, dass im Temperaturbereich bis 800°C Praseodym-Ionen an der Oberfläche des siliziumhaltigen Substratmaterials abstoßenden Kräften unterliegen, so dass es dort zu Si-O- Bindungen und nicht zu Si-Pr-Bindungen kommt. Das heißt, es werden an der Grenzfläche zum Substrat keine Suizide gebildet. Die stattdessen entstehenden Si-O-Bindungen an der Grenzfläche bewirken besonders gute elektrische Eigenschaften, wie sie von der SiO2/Si(001)-Grenzfläche her bekannt sind. Es existiert demnach eine chemisch reaktive Interface, die aus einem Si-Pr- Mischoxid der Form (Pr2O3)x(SiO2)1-x besteht, das typischerweise nicht stöchi- ometrisch zusammengesetzt ist.This is achieved by growing a mixed oxide layer on the silicon-containing layer. This mixed oxide layer contains silicon, praseodymium and oxygen. It is of great importance for the interface quality and thus for the mobility of the charge carriers that no suicides are formed in the semiconductor component according to the invention at the interface with the substrate. The fact that praseodymium ions on the surface of the silicon-containing substrate material are subject to repulsive forces in the temperature range up to 800 ° C. is used here in an inventive manner, so that there are Si-O bonds and not Si-Pr bonds. This means that no suicides are formed at the interface with the substrate. The Si-O bonds that form instead at the interface result in particularly good electrical properties, as are known from the SiO 2 / Si (001) interface. Accordingly, there is a chemically reactive interface consisting of a mixed Si-Pr oxide of the form (Pr 2 O 3 ) x (SiO 2 ) 1-x , which is typically not stoichiometrically composed.
Die erfindungsgemäß vorgegebene Temperaturobergrenze von 700°C verhindert ein Zersetzen von Strukturelementen des entstehenden Bauelements, insbesondere der Mischoxidschicht selbst.The upper temperature limit of 700 ° C. specified according to the invention prevents decomposition of structural elements of the resulting component, in particular the mixed oxide layer itself.
Bevorzugt erfolgen die Schritte des Abscheidens einer Mischoxidschicht und des Abscheidens einer Praseodymoxidschicht in Form eines Abscheidens aus der Gasphase. Auf diese Weise gelingt ein besonders kontrolliertes Wachstum dieser Schichten. Die genannten Abscheideschritte können mittels Molekularstrahlabscheidung (Molekularstrahlepitaxie, Molecular Beam Epitaxy, MBE) oder mittels chemischer Gasphasenabscheidung (Chemical Vapor Deposition, CVD) erfolgen.
Bei einem besonders bevorzugten Ausführungsbeispiel des erfindungsgemäßen Verfahrens erfolgt der Schritt des Abscheidens der Mischoxidschicht in einer sauerstoffhaltigen Gasatmosphäre. Wie weiter unten anhand von Figur 1 näher erläutert wird, hat sich gezeigt, dass die Gegenwart von Sauerstoff in der Gasatmosphäre der Wachstumskammer eine große Bedeutung für die Kontrolle der Schichtzusammensetzung hat. So entsteht insbesondere bei einem Mangel an Sauerstoff statt Siliziumdioxid SiO2 Siliziummonoxid SiO. Mit Hilfe des Sauerstoffangebots kann die Zusammensetzung, das heißt der Stö- chiometriekoeffizient x des Silikats (Pr203)x(SiO2)1-x gesteuert werden. Ein Sauerstoffüberangebot ist von großer Wichtigkeit für das Entstehen der Si-O- Bindungen im Bereich der Grenzfläche aufgrund der hohen Reaktivität von Silizium aus der siliziumhaltigen Schicht und Sauerstoff.The steps of depositing a mixed oxide layer and depositing a praseodymium oxide layer preferably take the form of deposition from the gas phase. In this way, a particularly controlled growth of these layers is achieved. The deposition steps mentioned can be carried out by means of molecular beam deposition (molecular beam epitaxy, Molecular Beam Epitaxy, MBE) or by means of chemical vapor deposition (Chemical Vapor Deposition, CVD). In a particularly preferred embodiment of the method according to the invention, the step of depositing the mixed oxide layer takes place in an oxygen-containing gas atmosphere. As will be explained in more detail below with reference to FIG. 1, it has been shown that the presence of oxygen in the gas atmosphere of the growth chamber is of great importance for the control of the layer composition. Thus, in particular when there is a lack of oxygen, silicon monoxide SiO is formed instead of silicon dioxide SiO 2 . The composition, ie the stoichiometric coefficient x of the silicate (Pr 2 0 3 ) x (SiO 2 ) 1-x can be controlled with the aid of the oxygen supply. An excess of oxygen is of great importance for the formation of the Si-O bonds in the area due to the high reactivity of silicon from the silicon-containing layer and oxygen.
Auch für das Abscheiden der Praseodymoxidschicht ist eine sauerstoffhaltige Gasatmosphäre vorteilhaft. Vorzugsweise kommt als ein Ausgangsmaterial für den Schritt des Abscheidens der Mischoxidschicht ein Material zum Einsatz, das Praseodymoxid in der Form Pr6Oιι enthält oder sogar vollständig daraus besteht. Die Reduktion von Praseodymoxid Pr6On in der Wachstumskammer sorgt für einen Sauer- stoffpartialdruck, mit dem das Schichtwachstum in der gewünschten Weise erfolgt. Mit Hilfe der Temperatur kann der Sauerstoffgehalt der Gasatmosphäre bei dieser Ausführungsform gesteuert werden.An oxygen-containing gas atmosphere is also advantageous for the deposition of the praseodymium oxide layer. Preferably, a material is used as a starting material for the step of depositing the mixed oxide layer, which contains praseodymium oxide in the form Pr 6 Oιι or even consists entirely of it. The reduction of praseodymium oxide Pr 6 On in the growth chamber ensures an oxygen partial pressure with which the layer growth takes place in the desired manner. With the aid of the temperature, the oxygen content of the gas atmosphere can be controlled in this embodiment.
Vorzugsweise erfolgt der Schritt des Abscheidens der Mischoxidschicht bei einer Substrattemperatur von weniger als 680°C, insbesondere zwischen 600 °C und 650 °C. In diesem Temperaturbereich kann insbesondere bei Verwendung von PrβO-n als Ausgangsmaterial ein ausreichendes Sauerstoffangebot gewährleistet werden, , das zur Bildung des Mischoxids (Pr203)x(SiO2)1-x führt.The step of depositing the mixed oxide layer preferably takes place at a substrate temperature of less than 680 ° C., in particular between 600 ° C. and 650 ° C. In this temperature range, in particular when using PrβO-n as the starting material, a sufficient supply of oxygen can be ensured, which leads to the formation of the mixed oxide (Pr 2 0 3 ) x (SiO2) 1-x .
Nachfolgend wird die Erfindung anhand zweier Zeichnungen näher erläutert. Es zeigen: Figur 1 ein ternäres Phasendiagramm für das System Praseodym- Sauerstoff-Silizium und
Figur 2 ein Ausführungsbeispiel eines erfindungsgemäßen Halbleiterbauelements.The invention is explained in more detail below with the aid of two drawings. FIG. 1 shows a ternary phase diagram for the system praseodymium-oxygen-silicon and Figure 2 shows an embodiment of a semiconductor device according to the invention.
Figur 1 zeigt ein ternäres Phasendiagramm für das System Praseodym- Sauerstoff-Silizium. Dieses Phasendiagramm wurde im Rahmen von For- schungsarbeiten im Zusammenhang mit der vorliegenden Erfindung experimentell ermittelt.Figure 1 shows a ternary phase diagram for the praseodymium-oxygen-silicon system. This phase diagram was determined experimentally in the context of research work in connection with the present invention.
Das Phasendiagramm weist drei Koordinatenachsen 10, 12 und 14 auf, die in der Form eines gleichseitigen Dreickes angeordnet sind. Den Eckpunkten des gleichseitigen Dreiecks sind die Elemente Praseodym, Sauerstoff und Silizium zugeordnet. Die Konzentration dieser Elemente entspricht dort dem Wert 1. Entlang den Seiten des Dreiecks sinkt die Konzentration des jeweiligen Elementes bis auf den Wert Null.The phase diagram has three coordinate axes 10, 12 and 14, which are arranged in the form of an equilateral triangle. The corner points of the equilateral triangle are assigned the elements praseodymium, oxygen and silicon. The concentration of these elements corresponds to the value 1. Along the sides of the triangle, the concentration of the respective element drops to the value zero.
Bei einem Siliziumgehalt 0,5 liegt Siliziummonoxid SiO vor. Dieser Punkt des Phasendiagramms ist mit dem Bezugszeichen 16 gekennzeichnet. Bei einem Siliziumgehalt von 0,33 liegt Siliziumdioxid SiO2 vor. Dieser Punkt des Phasendiagramms ist mit dem Bezugszeichen 18 gekennzeichnet. Entlang der Koordinatenachse 14 enthält die Phase ausschließlich Praseodym und Sauerstoff und kein Silizium. Eingezeichnet ist der Punkt 20, bei dem Praseodymoxid in der Form Pr2O3 vorliegt. In Form von Quadraten sind verschiedene experimentell ermittelte Phasen des Mischoxids innerhalb des von den drei Koordinatenachsen 10, 12 und 14 gebildeten Dreiecks dargestellt. Die experimentellen Werte wurden mit Hilfe der Photoelektronenspektroskopie anhand von im Temperaturbereich von 600 bis 650 °C gewachsenen Proben ermittelt. Zur Ermittlung ihrer Zusammenset- zung wurden die Proben mit Synchrotronstrahlung angeregt und die Energie der aus der Probe austretenden Elektronen aufgezeichnet und analysiert. Es zeigt sich, dass die ermittelten Phasen je nach Sauerstoffgehalt auf einer quasibinären Schnittlinie 22 liegen, die eine Mischphase von Praseodymoxid Pr2O und Siliziummonoxid SiO darstellt, oder auf einer quasibinären Schnitt- gerade 24, die eine Mischphase von Praseodymoxid Pr203 und Siliziumdioxid Si02 darstellt. An einem Punkt 25, bei dem die Schnittlinie 24 die vom Scheitel zur Basis führende Mittelsenkrechte des dreieckigen Phasendiagramms schneidet, wurde eine (Pr203)x(SiO2)1-x Thortveitit-Struktur ermittelt. An diesem
Punkt 25 des Phasendiagramms sind der Anteil von Silizium und Praseodym im Mischoxid gleich.With a silicon content of 0.5, silicon monoxide SiO is present. This point of the phase diagram is identified by reference number 16. With a silicon content of 0.33, silicon dioxide SiO 2 is present. This point of the phase diagram is identified by the reference symbol 18. Along the coordinate axis 14, the phase contains only praseodymium and oxygen and no silicon. The point 20 is shown, at which praseodymium oxide is in the form Pr 2 O 3 . Various experimentally determined phases of the mixed oxide within the triangle formed by the three coordinate axes 10, 12 and 14 are shown in the form of squares. The experimental values were determined with the aid of photoelectron spectroscopy using samples grown in the temperature range from 600 to 650 ° C. To determine their composition, the samples were excited with synchrotron radiation and the energy of the electrons emerging from the sample was recorded and analyzed. It can be seen that the phases determined, depending on the oxygen content, lie on a quasi-binary cut line 22, which represents a mixed phase of praseodymium oxide Pr 2 O and silicon monoxide SiO, or on a quasi-binary cut line 24, which is a mixed phase of praseodymium oxide Pr 2 0 3 and Silicon dioxide Si0 2 represents. A (Pr 2 0 3 ) x (SiO 2 ) 1-x thortveitite structure was determined at a point 25 at which the intersection line 24 intersects the perpendicular bisector of the triangular phase diagram leading from the vertex to the base. At this Point 25 of the phase diagram shows that the proportion of silicon and praseodymium in the mixed oxide is the same.
Das Phasendiagramm der Figur 1 zeigt demnach, dass es gelungen ist, ein Praseodymsilikat bzw. eine pseudobinäre, nicht stöchiometrische Legierung (Pr203)x(SiO2)1-x mit einstellbarem Anteil x des Praseodymoxids Pr203 herzustellen.The phase diagram in FIG. 1 accordingly shows that it has been possible to produce a praseodymium silicate or a pseudobinary, non-stoichiometric alloy (Pr 2 0 3 ) x (SiO 2 ) 1-x with an adjustable proportion x of the praseodymium oxide Pr 2 0 3 .
Figur 2 zeigt einen Ausschnitt eines Ausführungsbeispiels eines erfindungsgemäßen Halbleiterbauelements 30 mit einem Siliziumsubstrat 32, und einer daran angrenzenden Mischoxidschicht 34. An einer Grenzfläche 36 zwischen dem Siliziumsubstrat 32 und der Mischoxidschicht 34 weist das Substrat eine (001 )-Oberfläche auf. Bei der Mischoxidschicht handelt es sich um eine (Pr203)x(SiO2)1-x-Schicht, bei der der Koeffizient x an der Grenzfläche 36 einen Wert 0,3 und an einer Grenzfläche 38 zu einer benachbarten Praseodymoxidschicht (Pr203) 40 einen Wert 1 aufweist. Oberhalb der Praseodymoxidschicht 40 ist eine Polysiliziumschicht 42 angeordnet.FIG. 2 shows a section of an exemplary embodiment of a semiconductor component 30 according to the invention with a silicon substrate 32 and an adjacent mixed oxide layer 34. At an interface 36 between the silicon substrate 32 and the mixed oxide layer 34, the substrate has a (001) surface. The mixed oxide layer is a (Pr 2 0 3 ) x (SiO 2 ) 1-x layer in which the coefficient x has a value of 0.3 at the interface 36 and at an interface 38 to an adjacent praseodymium oxide layer (Pr 2 0 3 ) 40 has a value of 1. A polysilicon layer 42 is arranged above the praseodymium oxide layer 40.
Das Substrat 32 ist hier in seiner inneren Struktur nicht näher dargestellt. Das Bauelement 30, das hier auch lediglich in einem Ausschnitt gezeigt ist, kann beispielsweise ein MOSFET oder ein Speicherelement eines DROM- Speichers sein.
The inner structure of the substrate 32 is not shown here. The component 30, which is also shown here only in a section, can be, for example, a MOSFET or a memory element of a DROM memory.
Claims
1. Halbleiterbauelement (30) mit einer siliziumhaltigen Schicht (32) und einer Praseodymoxidschicht (40), dadurch gekennzeichnet, dass zwischen der siliziumhaltigen Schicht (32) und der Praseodymoxidschicht (40) eine Mischoxidschicht (34) enthaltend Silizium, Praseodym und Sauerstoff angeordnet ist, die eine Schichtdicke von weniger als 5 Nanometern aufweist.1. Semiconductor component (30) with a silicon-containing layer (32) and a praseodymium oxide layer (40), characterized in that a mixed oxide layer (34) containing silicon, praseodymium and oxygen is arranged between the silicon-containing layer (32) and the praseodymium oxide layer (40) , which has a layer thickness of less than 5 nanometers.
2. Halbleiterbauelement nach Anspruch 1 , bei dem die Mischoxid- Schicht (34) eine Schichtdicke von maximal 3 Nanometern aufweist.2. The semiconductor component according to claim 1, wherein the mixed oxide layer (34) has a layer thickness of at most 3 nanometers.
3. Halbleiterbauelement nach einem der vorstehenden Ansprüche, bei dem das Mischoxid (34) ein pseudobinäres, nicht stöchiometrisches Silikat oder eine Legierung des Typs (Pr203)x(SiO2)1-xist.3. Semiconductor component according to one of the preceding claims, wherein the mixed oxide (34) is a pseudobinary, non-stoichiometric silicate or an alloy of the type (Pr 2 0 3 ) x (SiO2) 1-x .
4. Halbleiterbauelement nach Anspruch 3, bei dem x zwischen der siliziumhaltigen Schicht (32) und der Praseodymoxidschicht (40) ansteigt.4. The semiconductor device according to claim 3, wherein x increases between the silicon-containing layer (32) and the praseodymium oxide layer (40).
5. Halbleiterbauelement nach einem der vorstehenden Ansprüche, bei dem die siliziumhaltige Schicht (32) aus dotiertem oder undotiertem Silizium-Germanium besteht.5. Semiconductor component according to one of the preceding claims, in which the silicon-containing layer (32) consists of doped or undoped silicon germanium.
6. Halbleiterbauelement nach einem der Ansprüche 1 bis 4, bei dem die siliziumhaltige Schicht aus dotiertem oder undotiertem Silizium besteht. 6. Semiconductor component according to one of claims 1 to 4, in which the silicon-containing layer consists of doped or undoped silicon.
7. Halbleiterbauelement nach Anspruch 5 oder 6, bei dem die Silizium-Germanium-Schicht bzw. die Siliziumschicht an der Grenzfläche zur Mischoxidschicht eine (001 )-Orientierung7. The semiconductor component as claimed in claim 5 or 6, in which the silicon-germanium layer or the silicon layer at the interface with the mixed oxide layer has a (001) orientation
8. Ü SET nach einem der vorstehenden Ansprüche.8. Ü SET according to one of the preceding claims.
9. Speicherzelle nach einem der Ansprüche 1 bis 7. 9. Memory cell according to one of claims 1 to 7.
10. Herstellungsverfahren für ein elektronisches Bauelement mit einem Schritt des Abscheidens einer Praseodymoxidschicht (40) auf einer siliziumhaltigen Schicht (32), dadurch gekennzeichnet, dass vor dem genannten Abschei- deschritt ein Schritt des Abscheidens einer Mischoxidschicht (34) enthaltend Silizium, Praseodym und Sauerstoff bei einer Substrattemperatur von weniger als 700°C erfolgt.10. A production method for an electronic component with a step of depositing a praseodymium oxide layer (40) on a silicon-containing layer (32), characterized in that before said deposition step, a step of depositing a mixed oxide layer (34) containing silicon, praseodymium and oxygen at a substrate temperature of less than 700 ° C.
11. Verfahren nach Anspruch 10, bei dem die Schritte des Abscheidens einer Mischoxidschicht (34) und des Abscheidens einer Praseodymoxidschicht (40) in Form eines Abscheidens aus der11. The method of claim 10, wherein the steps of depositing a mixed oxide layer (34) and depositing a praseodymium oxide layer (40) in the form of a deposit from the
Gasphase erfolgen.Gas phase.
12. Verfahren nach Anspruch 1 1 , bei dem die Abscheideschritte mittels Molekularstrahlabscheidung erfolgen.12. The method according to claim 1 1, wherein the deposition steps are carried out by means of molecular beam deposition.
13. Verfahren nach Anspruch 11 , bei dem die Abscheideschritte mit- tels chemischer Gasphasenabscheidung erfolgen.13. The method according to claim 11, in which the deposition steps are carried out by means of chemical vapor deposition.
14. Verfahren nach einem der Ansprüche 10 bis 13, bei dem der Schritt des Abscheidens der Mischoxidschicht (34) in einer sau- erstoffhaltigen Gasatmosphäre erfolgt.14. The method according to any one of claims 10 to 13, wherein the step of depositing the mixed oxide layer (34) is carried out in an oxygen-containing gas atmosphere.
15. Verfahren nach einem der Ansprüche 10 bis 14, bei dem der Schritt des Abscheidens der Praseodymoxidschicht (40) in einer sauerstoffhaltigen Gasatmosphäre erfolgt.15. The method according to any one of claims 10 to 14, wherein the step of depositing the praseodymium oxide layer (40) is carried out in an oxygen-containing gas atmosphere.
16. Verfahren nach einem der Ansprüche 10 bis 15, bei dem der Schritt des Abscheidens der Mischoxidschicht (34) mit Hilfe eines Ausgangsmaterials erfolgt, das Praseodymoxid in der Form Pr6On enthält oder daraus besteht.16. The method according to any one of claims 10 to 15, wherein the step of depositing the mixed oxide layer (34) is carried out with the aid of a starting material which contains or consists of praseodymium oxide in the form Pr 6 On.
17. Verfahren nach einem der Ansprüche 10 bis 16, bei dem der Schritt des Abscheidens der Praseodymoxidschicht (40) mit Hilfe eines Praseodymoxid in der Form Pr6On enthaltenden Ausgangsmaterials erfolgt. 17. The method according to any one of claims 10 to 16, wherein the step of depositing the praseodymium oxide layer (40) with the aid of a praseodymium oxide in the form Pr 6 On containing starting material.
18. Verfahren nach einem der Ansprüche 10 bis 17, bei dem der Schritt des Abscheidens der Mischoxidschicht (34) bei einer Temperatur von maximal 680°C erfolgt.18. The method according to any one of claims 10 to 17, wherein the step of depositing the mixed oxide layer (34) takes place at a temperature of at most 680 ° C.
19. Verfahren nach einem der Ansprüche 12 bis 17, bei dem der Schritt des Abscheidens der Mischoxidschicht (34) bei einer Temperatur zwischen 600°C und 650°C erfolgt. 19. The method according to any one of claims 12 to 17, wherein the step of depositing the mixed oxide layer (34) takes place at a temperature between 600 ° C and 650 ° C.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10245590A DE10245590A1 (en) | 2002-09-26 | 2002-09-26 | Semiconductor device with praseodymium oxide dielectric |
DE10245590 | 2002-09-26 | ||
PCT/EP2003/010625 WO2004032216A1 (en) | 2002-09-26 | 2003-09-24 | Semi-conductor dielectric component with a praseodymium oxide dielectric |
Publications (1)
Publication Number | Publication Date |
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EP1547135A1 true EP1547135A1 (en) | 2005-06-29 |
Family
ID=32009990
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP03769314A Withdrawn EP1547135A1 (en) | 2002-09-26 | 2003-09-24 | Semi-conductor dielectric component with a praseodymium oxide dielectric |
Country Status (4)
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US (1) | US20060138501A1 (en) |
EP (1) | EP1547135A1 (en) |
DE (1) | DE10245590A1 (en) |
WO (1) | WO2004032216A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
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DE10309728B4 (en) * | 2003-02-26 | 2009-06-04 | IHP GmbH - Innovations for High Performance Microelectronics/Institut für innovative Mikroelektronik | Process for producing Si wafers with a lanthanoid silicate layer |
DE10340202A1 (en) * | 2003-08-28 | 2005-04-14 | IHP GmbH - Innovations for High Performance Microelectronics/Institut für innovative Mikroelektronik | Manufacturing Method for Semiconductor Device with Praseodymium Oxide Dielectric |
DE102005051573B4 (en) * | 2005-06-17 | 2007-10-18 | IHP GmbH - Innovations for High Performance Microelectronics/Institut für innovative Mikroelektronik | MIM / MIS structure with praseodymium titanate as insulator material |
Family Cites Families (7)
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DE10039327A1 (en) * | 2000-08-03 | 2002-02-14 | Ihp Gmbh | Electronic component and manufacturing method for electronic component |
US6734453B2 (en) * | 2000-08-08 | 2004-05-11 | Translucent Photonics, Inc. | Devices with optical gain in silicon |
US6593618B2 (en) * | 2000-11-28 | 2003-07-15 | Kabushiki Kaisha Toshiba | MIS semiconductor device having an elevated source/drain structure |
US20020089023A1 (en) * | 2001-01-05 | 2002-07-11 | Motorola, Inc. | Low leakage current metal oxide-nitrides and method of fabricating same |
FR2833106B1 (en) * | 2001-12-03 | 2005-02-25 | St Microelectronics Sa | INTEGRATED CIRCUIT INCLUDING AN AUXILIARY COMPONENT, FOR EXAMPLE A PASSIVE COMPONENT OR AN ELECTROMECHANICAL MICROSYSTEM, PROVIDED ABOVE AN ELECTRONIC CHIP, AND CORRESPONDING MANUFACTURING METHOD |
US6656852B2 (en) * | 2001-12-06 | 2003-12-02 | Texas Instruments Incorporated | Method for the selective removal of high-k dielectrics |
US7205218B2 (en) * | 2002-06-05 | 2007-04-17 | Micron Technology, Inc. | Method including forming gate dielectrics having multiple lanthanide oxide layers |
-
2002
- 2002-09-26 DE DE10245590A patent/DE10245590A1/en not_active Ceased
-
2003
- 2003-09-24 EP EP03769314A patent/EP1547135A1/en not_active Withdrawn
- 2003-09-24 WO PCT/EP2003/010625 patent/WO2004032216A1/en not_active Application Discontinuation
- 2003-09-24 US US10/528,868 patent/US20060138501A1/en not_active Abandoned
Non-Patent Citations (1)
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See references of WO2004032216A1 * |
Also Published As
Publication number | Publication date |
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DE10245590A1 (en) | 2004-04-15 |
US20060138501A1 (en) | 2006-06-29 |
WO2004032216A1 (en) | 2004-04-15 |
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