US20090236680A1 - Semiconductor device with a semiconductor body and method for its production - Google Patents
Semiconductor device with a semiconductor body and method for its production Download PDFInfo
- Publication number
- US20090236680A1 US20090236680A1 US12/052,019 US5201908A US2009236680A1 US 20090236680 A1 US20090236680 A1 US 20090236680A1 US 5201908 A US5201908 A US 5201908A US 2009236680 A1 US2009236680 A1 US 2009236680A1
- Authority
- US
- United States
- Prior art keywords
- doping
- zones
- semiconductor
- doping material
- conduction type
- 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.)
- Abandoned
Links
- 239000004065 semiconductor Substances 0.000 title claims abstract description 116
- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 10
- 239000000463 material Substances 0.000 claims abstract description 126
- 238000005468 ion implantation Methods 0.000 claims abstract description 50
- 238000009792 diffusion process Methods 0.000 claims abstract description 19
- 230000003698 anagen phase Effects 0.000 claims description 46
- 230000000295 complement effect Effects 0.000 claims description 18
- 230000015556 catabolic process Effects 0.000 claims description 11
- 229910052710 silicon Inorganic materials 0.000 claims description 5
- 239000010703 silicon Substances 0.000 claims description 5
- 239000000758 substrate Substances 0.000 claims description 4
- 238000009826 distribution Methods 0.000 claims description 3
- 230000001427 coherent effect Effects 0.000 claims description 2
- 230000012010 growth Effects 0.000 claims description 2
- 238000007796 conventional method Methods 0.000 claims 1
- 238000005520 cutting process Methods 0.000 claims 1
- 239000002800 charge carrier Substances 0.000 description 7
- 238000000407 epitaxy Methods 0.000 description 4
- 239000013078 crystal Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- 229910052796 boron Inorganic materials 0.000 description 2
- 238000002513 implantation Methods 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000010297 mechanical methods and process Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
Images
Classifications
-
- 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
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/78—Field effect transistors with field effect produced by an insulated gate
- H01L29/7801—DMOS transistors, i.e. MISFETs with a channel accommodating body or base region adjoining a drain drift region
- H01L29/7802—Vertical DMOS transistors, i.e. VDMOS transistors
-
- 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
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/0603—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions
- H01L29/0607—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration
- H01L29/0611—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration for increasing or controlling the breakdown voltage of reverse biased devices
- H01L29/0615—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration for increasing or controlling the breakdown voltage of reverse biased devices by the doping profile or the shape or the arrangement of the PN junction, or with supplementary regions, e.g. junction termination extension [JTE]
- H01L29/063—Reduced surface field [RESURF] pn-junction structures
- H01L29/0634—Multiple reduced surface field (multi-RESURF) structures, e.g. double RESURF, charge compensation, cool, superjunction (SJ), 3D-RESURF, composite buffer (CB) structures
-
- 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
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/08—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions with semiconductor regions connected to an electrode carrying current to be rectified, amplified or switched and such electrode being part of a semiconductor device which comprises three or more electrodes
- H01L29/0843—Source or drain regions of field-effect devices
- H01L29/0847—Source or drain regions of field-effect devices of field-effect transistors with insulated gate
- H01L29/0852—Source or drain regions of field-effect devices of field-effect transistors with insulated gate of DMOS transistors
- H01L29/0873—Drain regions
- H01L29/0878—Impurity concentration or distribution
-
- 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
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/10—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions with semiconductor regions connected to an electrode not carrying current to be rectified, amplified or switched and such electrode being part of a semiconductor device which comprises three or more electrodes
- H01L29/1095—Body region, i.e. base region, of DMOS transistors or IGBTs
-
- 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
- H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
- H01L29/417—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions carrying the current to be rectified, amplified or switched
- H01L29/41725—Source or drain electrodes for field effect devices
- H01L29/41766—Source or drain electrodes for field effect devices with at least part of the source or drain electrode having contact below the semiconductor surface, e.g. the source or drain electrode formed at least partially in a groove or with inclusions of conductor inside the semiconductor
-
- 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
- H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
- H01L29/423—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions not carrying the current to be rectified, amplified or switched
- H01L29/42312—Gate electrodes for field effect devices
- H01L29/42316—Gate electrodes for field effect devices for field-effect transistors
- H01L29/4232—Gate electrodes for field effect devices for field-effect transistors with insulated gate
- H01L29/42364—Gate electrodes for field effect devices for field-effect transistors with insulated gate characterised by the insulating layer, e.g. thickness or uniformity
- H01L29/42368—Gate electrodes for field effect devices for field-effect transistors with insulated gate characterised by the insulating layer, e.g. thickness or uniformity the thickness being non-uniform
-
- 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
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66477—Unipolar field-effect transistors with an insulated gate, i.e. MISFET
- H01L29/66674—DMOS transistors, i.e. MISFETs with a channel accommodating body or base region adjoining a drain drift region
- H01L29/66712—Vertical DMOS transistors, i.e. VDMOS transistors
- H01L29/66727—Vertical DMOS transistors, i.e. VDMOS transistors with a step of recessing the source electrode
-
- 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
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/80—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier
- H01L29/808—Field effect transistors with field effect produced by a PN or other rectifying junction gate, i.e. potential-jump barrier with a PN junction gate, e.g. PN homojunction gate
- H01L29/8083—Vertical transistors
Definitions
- the application relates to a semiconductor device with a semiconductor body and to a method for its production.
- the semiconductor body includes drift zones of epitaxially grown semiconductor material of a first conduction type.
- the semiconductor body further includes charge compensation zones of a second conduction type complementing the first conduction type, which are arranged laterally adjacent to the drift zones.
- the charge compensation zones are provided with a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material.
- a minimum on resistance is desirable in charge compensation devices of this type.
- the level of drift zone doping material has to be increased further.
- the doping of the charge compensation zones has to be increased in the same way.
- the geometrical period in the form of the step size of the charge compensation zones and possibly even of the drift zones has to be reduced further at the same time.
- the concentration of doping material per unit of area as integrated in the horizontal direction must not be higher than twice the breakdown charge.
- breakdown charge denotes the charge carrier quantity (doping material concentration quantity) per unit of area which, starting from a p-n junction, is depleted if the breakdown field strength is applied.
- the requirement that the regions should be capable of being depleted is equivalent to the requirement that the concentration of doping material per unit of area as integrated in the horizontal direction should not be higher than twice the breakdown charge. These conditions have to be met both by the compensation regions and by the drift zones. Similar to the breakdown field strength, the breakdown charge is determined by the concentration of doping material; for silicon is lies between 1 ⁇ 10 12 cm ⁇ 2 at low doping and 3 ⁇ 10 12 cm ⁇ 2 at high doping.
- the regions of a complementary conduction type for the charge compensation zones which are introduced by masked or selective ion implantation and typically doped with boron, have to diffuse together through the epitaxial growth phases of finite thickness. This however unavoidably involves major widening of the columns or strips of charge compensation zone material.
- non-doped epitaxial layers can be grown in the epitaxial growth phase, whereupon both doping materials of the first conduction type and doping materials of the complementary second conduction type can be introduced in succession by ion implantation near the surface between individual epitaxial growth phases, so that the widening caused by lateral outdiffusion while the charge compensation zones diffuse together can be noticeably reduced by a relatively high adjacent n-doping of the drift zones.
- n-doping in the middle of the epitaxial growth phase is relatively low can only be compensated by raising the general level of implanted doping material in order to reduce the on resistance.
- a high level of doping material automatically complicates the manufacturing process, as breakdown voltage is highly dependent on wrong doping. The higher the level of doping material, the higher are its fluctuations and the more difficult is it to obtain the required breakdown voltage.
- An embodiment of the invention relates to a semiconductor device with a semiconductor body.
- the semiconductor body includes drift zones of epitaxially grown semiconductor material of a first conduction type.
- the semiconductor body further includes charge compensation zones of a second conduction type complementing the first conduction type, which are arranged laterally adjacent to the drift zones.
- the charge compensation zones are provided with a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material.
- the epitaxially grown semiconductor material contains 20 to 80 atomic % of the doping material of the drift zones and a doping material balance between 80 and 20 atomic % introduced by ion implantation and diffusion.
- FIGS. 1-8 illustrate production processes for a semiconductor device of an embodiment of the invention.
- FIG. 1 illustrates a diagrammatic cross-section through a semiconductor wafer.
- FIG. 2 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 1 following the completion of a first epitaxial growth phase with homogeneous doping of the epitaxial layer.
- FIG. 3 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 2 following the large-area unmasked ion implantation of a doping material balance for a first conduction type.
- FIG. 4 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 3 following the masked selective ion implantation of a complementary second conduction type.
- FIG. 5 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 4 following a second epitaxial growth phase and a large-area unmasked ion implantation of a doping material balance of the first conduction type.
- FIG. 6 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 5 following the masked selective ion implantation of a doping material of a complementary second conduction type.
- FIG. 7 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases.
- FIG. 8 illustrates a diagrammatic cross-section through the section according to FIG. 7 following the diffusing together of the implanted charge compensation zone doping to form a column- or strip-shaped charge compensation zone.
- FIG. 9 illustrates a diagram of the concentration behaviour of the doping material of the first conduction type in a drift zone.
- FIGS. 10-18 illustrate production processes for a semiconductor device of a further embodiment of the invention.
- FIG. 10 illustrates a diagrammatic cross-section through a semiconductor wafer.
- FIG. 11 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 10 following the completion of a first epitaxial growth phase with inhomogeneous doping of the epitaxial layer.
- FIG. 12 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 11 following the large-area unmasked ion implantation of a doping material balance for a first conduction type.
- FIG. 13 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 12 following the masked selective ion implantation of a doping material for a complementary second conduction type.
- FIG. 14 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 13 following a second epitaxial growth phase and a large-area unmasked ion implantation of a doping material balance of a first conduction type.
- FIG. 15 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 14 following the masked selective ion implantation of a doping material of a complementary second conduction type.
- FIG. 16 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases.
- FIG. 17 illustrates a diagrammatic cross-section through the section according to FIG. 16 following the diffusing together of the implanted charge compensation zone doping to form a column- or strip-shaped charge compensation zone.
- FIG. 18 is a diagram illustrating further reduced fluctuations of the charge carrier concentration in the drift zone.
- FIG. 19 illustrates a diagrammatic cross-section through a semiconductor device according to an embodiment of the invention.
- FIG. 1 illustrates a diagrammatic cross-section through a semiconductor wafer 16 , which can be used as a semiconductor substrate 17 for a variety of semiconductor devices.
- This semiconductor wafer 16 may, for example, initially be highly doped with a doping material for a first conduction type, thus being n + -conducting, to produce MOSFET power transistors with a compensation structure.
- doping materials arsenic or phosphorus may be introduced during the single crystal growing phase in concentrations between 5 ⁇ 10 18 cm ⁇ 3 and 5 ⁇ 10 20 cm ⁇ 3 or generated in the crystal by appropriate neutron bombardment.
- a first epitaxial layer is deposited on the front side 20 , which has been polished mirror-bright in a chemical-mechanical process, in a first epitaxial growth phase.
- FIG. 2 illustrates a diagrammatic cross-section through the semiconductor wafer 16 according to FIG. 1 following the completion of a first epitaxial growth phase.
- a thickness d of n-type silicon is grown in a monocrystalline manner; in this first embodiment of the invention, 20 to 80 atomic % of the doping material for drift zones are homogeneously distributed in this epitaxial layer.
- the missing doping material quantity of 80 to 20 atomic % can be introduced near the surface by ion implantation to limit the widening of the compensation regions by the lateral diffusion of the complementary-type doping materials for charge compensation zones.
- This homogeneous pre-doping which however only provides 20 to 80 atomic % of the doping materials of the drift zones, avoids the disadvantage of the relatively high resistance in the middle region of the epitaxial growth phase, which occurs in multiple epitaxial processes with non-doped epitaxial growth phases.
- a non-doped epitaxial layer is often applied, followed by the doping of the drift zones and the charge compensation zones by ion implantation.
- the pre-doping described above avoids such disadvantages of reduced conductivity in the middle of the epitaxial growth phase.
- the missing doping material balance between 80 and 20 atomic % can then be introduced near the surface by ion implantation as illustrated in FIG. 3 , thereby limiting the lateral widening of the charge compensation columns.
- the on resistance is affected both by wide compensation regions and by insufficiently high doping in the middle of the epitaxial growth phases. By using simulations, it can be shown that the on resistance can be minimized by the combination of two methods described above, i.e. the doping of the epitaxy and implantation between the epitaxial growth phases.
- FIG. 3 illustrates a diagrammatic cross-section through the semiconductor wafer 16 according to FIG. 2 following the ion implantation of a doping material balance ⁇ n for a first conduction type.
- a charge carrier concentration of n+ ⁇ n is obtained near the surface of the first epitaxial layer 18 by an additional ion implantation of, for example, phosphorus or arsenic for a first conduction type 4 of the drift zones.
- the near-surface zone with the doping material balance 9 of 80 to 20 atomic % of drift zone doping as illustrated in FIG. 3 will in the subsequent diffusion process be distributed in the illustrated epitaxial layer to a thickness d.
- FIG. 4 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 3 following the selective ion implantation of a complementary conduction type 7 in windows 23 of a previously applied ion implantation mask 22 for the second complementary conduction type 7 .
- Boron may be used as a doping material for the complementary conduction type 7 .
- concentration of doping material increased by ⁇ n prevails near the surface in the drift zone regions 3 , the lateral expansion of the charge compensation zone doping 8 in the subsequent diffusion process to form charge compensation zone columns or strips is limited, allowing for a smaller step size between the charge compensation zones and thus permitting a higher doping of the drift zones.
- FIG. 5 illustrates a diagrammatic cross-section through the semiconductor wafer 16 according to FIG. 4 following a second epitaxial growth phase and an ion implantation of a doping material balance of the first conduction type, which is once again introduced into this second epitaxial layer 24 unmasked, over a large area and near the surface.
- This ion implantation of the first conduction type 4 for the drift zone 3 does not require any diffusion mask for the near-surface introduction of the doping material balance 9 .
- Only the next process illustrated in FIG. 6 requires a suitable ion implantation mask 22 for the selective introduction of a doping material of a complementary conduction type.
- FIG. 6 illustrates a diagrammatic cross-section through the semiconductor wafer 16 according to FIG. 5 following the selective ion implantation of a doping material of a complementary second conduction type. This creates a further doping material reservoir in the open windows 23 of the ion implantation mask 22 , but without any connection to the complementary-type regions of the charge compensation zones as illustrated in FIG. 4 .
- FIG. 7 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases, wherein 20 to 80 atomic % of homogeneously distributed doping material of the first conduction type 4 have been introduced and the missing doping material balance is introduced near the surface in the regions 9 by ion implantation after each epitaxial growth phase, resulting in the structure illustrated in FIG. 7 , wherein the selectively introduced charge compensation zone doping 8 does not yet form a coherent charge compensation zone column or strip. This requires a further diffusion process, wherein the doping material balance 9 for the drift zones 3 is distributed further in the semiconductor material.
- FIG. 8 illustrates a diagrammatic cross-section through the section according to FIG. 7 following the diffusing together of the implanted charge compensation zone doping to form a column- or strip-shaped charge compensation zone 6 .
- Whether column- or strip-shaped charge compensation zones 6 are generated depends on the ion implantation mask prepared for the semiconductor device.
- the doping material balance ⁇ n has likewise been distributed further in the drift zones 3 by diffusion processes, so that relatively highly doped drift zones 3 of a small step size p in micrometers of p ⁇ 12 ⁇ m can be created, which reduces the on resistance of a semiconductor device with a drift zone structure of this type.
- FIG. 9 illustrates a diagram with optimised concentration fluctuations of the doping material in a drift zone.
- the doping material concentration N is plotted on the abscissa, while the penetration depth, which is a measure for the blocking capability of the semiconductor device, is plotted on the ordinate.
- concentration fluctuations are noticeably minimized owing to the homogeneous pre-doping of the epitaxial layers in the range of 20 to 80 atomic %.
- the homogeneously distributed proportion of doping material in the epitaxial growth phases can be limited to a third of the total concentration of doping material for the first conduction type, while two thirds subsequently have to be introduced near the surface by ion implantation.
- the proportion of doping material introduced by ion implantation is significantly larger than the proportion introduced into the semiconductor crystal by homogeneous doping in the epitaxial growth phase.
- Fluctuations in the concentration of doping material for the drift zones can be reduced further by using a technology and a manufacturing process described below with reference to FIGS. 10 to 18 and resulting in a semiconductor device illustrated in FIG. 19 .
- This method is likewise based on a semiconductor wafer 16 as illustrated in FIG. 10 , which is highly doped with an n + -type doping material.
- FIG. 11 illustrates a diagrammatic cross-section through the semiconductor wafer 16 according to FIG. 10 following the completion of a first epitaxial growth phase.
- the doping material is not introduced homogeneously, but rather inhomogeneously, i.e. the addition of doping material is reduced or stopped completely during the epitaxial growth process, resulting in a maximum of doping material approximately in the middle of the epitaxial growth phase.
- the boundaries of the region with a maximum doping n max are indicated by dot-dash lines in the epitaxial layer 18 of FIG. 11 .
- the relatively lightly doped, near-surface region is filled unmasked with the doping material balance over a large area by using ion implantation as illustrated in FIG. 12 .
- FIG. 13 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 12 following the selective ion implantation of a doping material for a complementary second conduction type.
- This FIG. 13 corresponds to FIG. 4 , and owing to the ion-implanted concentration of doping material, the lateral outdiffusion of the p-type material introduced by ion implantation is limited, allowing the production of compensated semiconductor devices with small step sizes of less than 12 ⁇ m.
- FIG. 14 illustrates a diagrammatic cross-section through the semiconductor wafer according to FIG. 13 following a second epitaxial growth phase and an ion implantation of a doping material balance of a first conduction type, which is once again introduced unmasked and over a large area into the semiconductor wafer. Moreover, a maximum n max of doping material is introduced in the middle of the growth phase during the second epitaxial growth phase, in order to increase the doping in the drift zone further and to ensure that the on resistance for a compensated device of this type is further reduced.
- n max of doping material is introduced in the middle of the growth phase during the second epitaxial growth phase, in order to increase the doping in the drift zone further and to ensure that the on resistance for a compensated device of this type is further reduced.
- FIG. 15 illustrates a diagrammatic cross-section through the semiconductor wafer 16 according to FIG. 14 following the selective ion implantation of a doping material of a complementary second conduction type in windows 23 of an ion implantation mask 22 , generating further p-type islands which are diffused together on completion of all of the epitaxial growth phases; in this process, the concentration of doping material in the drift zones becomes uniform.
- FIG. 16 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases, wherein initially a maximum doping n max of the first conduction type 4 is generated in each epitaxial growth phase, followed by the introduction of a doping material balance in the region of the future drift zones by large-area ion implantation.
- FIG. 17 illustrates a diagrammatic cross-section through the section according to FIG. 16 following the diffusing together of the implanted charge compensation zone doping 8 to form a column- or strip-shaped charge compensation zone 6 .
- This column 10 illustrates a reduced lateral outdiffusion between individual epitaxial growth phases, allowing for a smaller step size in combination with higher doping of the drift zones 3 .
- FIG. 18 illustrates further reduced fluctuations of the charge carrier concentration in the drift zone.
- the doping material concentration N is plotted on the abscissa, while the thickness or depth in the direction z of the individual epitaxial growth phases is once again plotted on the ordinate.
- the dot-dash line within each epitaxial growth phase indicates a maximum concentration of doping material introduced into each epitaxial layer, while ion implantation with a concentration of ⁇ n is carried out between the epitaxial growth phases, which in turn prevents the lateral outdiffusion of the complementary-conducting material for the charge compensation zones.
- the distribution of the charge carrier concentration ⁇ n introduced by ion implantation is indicated by broken lines, while the fluctuation of the charge carrier concentration in the drift zones after diffusion is indicated by a continuous line. Any fluctuations which are still noticeable are so negligible that the charge compensation zones and the drift zones can come closer together, allowing for a higher drift zone doping.
- FIG. 19 illustrates a diagrammatic cross-section through a semiconductor device 1 according to an embodiment wherein the lateral outdiffusion for the charge compensation zones 6 is significantly reduced by the methods described above, whereby the fluctuation of the doping material concentration in the drift zones is reduced in the vertical direction.
- This embodiment is a vertical MOSFET with a lateral gate structure, but the teaching of the invention can also be applied to JFET or other compensated device structures, provided that a multiple epitaxial structure is provided for the drift zone.
- the charge compensation zones are completed by the near-surface introduction of a p-type body zone 12 , which in turn accommodates a highly doped n + -type source zone 13 , wherein the highly doped n + -type source zone 13 and the body zone 12 are contacted by a metallic source electrode 14 , while a lateral gate structure insulated against the body zone 12 by a gate oxide 25 permits the control of this power transistor.
- a step size 15 of less than 12 ⁇ m can be achieved between the charge compensation zones.
- the substrate 17 or the original semiconductor wafer 16 can be ground thin, thus further minimising the on resistance of the semiconductor device 1 .
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Ceramic Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Recrystallisation Techniques (AREA)
- Thyristors (AREA)
Abstract
A semiconductor device with a semiconductor body and method for its production is provided. The semiconductor body includes drift zones of epitaxially grown semiconductor material of a first conduction type. The semiconductor body further includes charge compensation zones of a second conduction type complementing the first conduction type, which are arranged laterally adjacent to the drift zones. The charge compensation zones are provided with a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material. The epitaxially grown semiconductor material includes 20 to 80 atomic % of the doping material of the drift zones and a doping material balance of 80 to 20 atomic % introduced by ion implantation and diffusion.
Description
- The application relates to a semiconductor device with a semiconductor body and to a method for its production. The semiconductor body includes drift zones of epitaxially grown semiconductor material of a first conduction type. The semiconductor body further includes charge compensation zones of a second conduction type complementing the first conduction type, which are arranged laterally adjacent to the drift zones. The charge compensation zones are provided with a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material.
- A minimum on resistance is desirable in charge compensation devices of this type. In order to achieve a further reduction of this on resistance, the level of drift zone doping material has to be increased further. Owing to the compensation principle, however, the doping of the charge compensation zones has to be increased in the same way. In order to ensure a complete depletion of charge carriers from the drift zones in the off phase of the semiconductor device in spite of such an increase in the level of doping material both in the drift zones and in the charge compensation zones, the geometrical period in the form of the step size of the charge compensation zones and possibly even of the drift zones has to be reduced further at the same time. In other words, the concentration of doping material per unit of area as integrated in the horizontal direction must not be higher than twice the breakdown charge. The term breakdown charge denotes the charge carrier quantity (doping material concentration quantity) per unit of area which, starting from a p-n junction, is depleted if the breakdown field strength is applied. As the compensation regions are depleted from both sides, the requirement that the regions should be capable of being depleted is equivalent to the requirement that the concentration of doping material per unit of area as integrated in the horizontal direction should not be higher than twice the breakdown charge. These conditions have to be met both by the compensation regions and by the drift zones. Similar to the breakdown field strength, the breakdown charge is determined by the concentration of doping material; for silicon is lies between 1×1012 cm−2 at low doping and 3×1012 cm−2 at high doping.
- By using trench technology, wherein the charge compensation zones and/or the drift zones are arranged in trench structures, very small step sizes can be obtained in theory, but this technology has not yet penetrated the market, so that the concept of multiple epitaxy is used to build semiconductor devices of this type. In multiple epitaxy, epitaxial growth phases are interspersed with unmasked large-area and masked selective implantation processes for doping materials. To reduce costs, the number of epitaxial growth phases is limited.
- The regions of a complementary conduction type for the charge compensation zones, which are introduced by masked or selective ion implantation and typically doped with boron, have to diffuse together through the epitaxial growth phases of finite thickness. This however unavoidably involves major widening of the columns or strips of charge compensation zone material. To reduce this widening problem caused by lateral diffusion, non-doped epitaxial layers can be grown in the epitaxial growth phase, whereupon both doping materials of the first conduction type and doping materials of the complementary second conduction type can be introduced in succession by ion implantation near the surface between individual epitaxial growth phases, so that the widening caused by lateral outdiffusion while the charge compensation zones diffuse together can be noticeably reduced by a relatively high adjacent n-doping of the drift zones.
- However, initially high-impedance non-doped epitaxial layers are generated in the epitaxial growth phase, so that the on resistance of the drift zones cannot be reduced as desired. The n-doping in the middle of the epitaxial growth phase is relatively low can only be compensated by raising the general level of implanted doping material in order to reduce the on resistance. A high level of doping material, however, automatically complicates the manufacturing process, as breakdown voltage is highly dependent on wrong doping. The higher the level of doping material, the higher are its fluctuations and the more difficult is it to obtain the required breakdown voltage.
- For these and other reasons, there is a need for the present invention.
- An embodiment of the invention relates to a semiconductor device with a semiconductor body. The semiconductor body includes drift zones of epitaxially grown semiconductor material of a first conduction type. The semiconductor body further includes charge compensation zones of a second conduction type complementing the first conduction type, which are arranged laterally adjacent to the drift zones. The charge compensation zones are provided with a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material. The epitaxially grown semiconductor material contains 20 to 80 atomic % of the doping material of the drift zones and a doping material balance between 80 and 20 atomic % introduced by ion implantation and diffusion.
- The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification. The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles of the invention. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.
-
FIGS. 1-8 illustrate production processes for a semiconductor device of an embodiment of the invention. -
FIG. 1 illustrates a diagrammatic cross-section through a semiconductor wafer. -
FIG. 2 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 1 following the completion of a first epitaxial growth phase with homogeneous doping of the epitaxial layer. -
FIG. 3 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 2 following the large-area unmasked ion implantation of a doping material balance for a first conduction type. -
FIG. 4 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 3 following the masked selective ion implantation of a complementary second conduction type. -
FIG. 5 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 4 following a second epitaxial growth phase and a large-area unmasked ion implantation of a doping material balance of the first conduction type. -
FIG. 6 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 5 following the masked selective ion implantation of a doping material of a complementary second conduction type. -
FIG. 7 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases. -
FIG. 8 illustrates a diagrammatic cross-section through the section according toFIG. 7 following the diffusing together of the implanted charge compensation zone doping to form a column- or strip-shaped charge compensation zone. -
FIG. 9 illustrates a diagram of the concentration behaviour of the doping material of the first conduction type in a drift zone. -
FIGS. 10-18 illustrate production processes for a semiconductor device of a further embodiment of the invention. -
FIG. 10 illustrates a diagrammatic cross-section through a semiconductor wafer. -
FIG. 11 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 10 following the completion of a first epitaxial growth phase with inhomogeneous doping of the epitaxial layer. -
FIG. 12 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 11 following the large-area unmasked ion implantation of a doping material balance for a first conduction type. -
FIG. 13 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 12 following the masked selective ion implantation of a doping material for a complementary second conduction type. -
FIG. 14 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 13 following a second epitaxial growth phase and a large-area unmasked ion implantation of a doping material balance of a first conduction type. -
FIG. 15 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 14 following the masked selective ion implantation of a doping material of a complementary second conduction type. -
FIG. 16 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases. -
FIG. 17 illustrates a diagrammatic cross-section through the section according toFIG. 16 following the diffusing together of the implanted charge compensation zone doping to form a column- or strip-shaped charge compensation zone. -
FIG. 18 is a diagram illustrating further reduced fluctuations of the charge carrier concentration in the drift zone. -
FIG. 19 illustrates a diagrammatic cross-section through a semiconductor device according to an embodiment of the invention. - In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is illustrated by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope is defined by the appended claims.
-
FIG. 1 illustrates a diagrammatic cross-section through asemiconductor wafer 16, which can be used as asemiconductor substrate 17 for a variety of semiconductor devices. Thissemiconductor wafer 16 may, for example, initially be highly doped with a doping material for a first conduction type, thus being n+-conducting, to produce MOSFET power transistors with a compensation structure. As doping materials, arsenic or phosphorus may be introduced during the single crystal growing phase in concentrations between 5×1018 cm−3 and 5×1020 cm−3 or generated in the crystal by appropriate neutron bombardment. A first epitaxial layer is deposited on thefront side 20, which has been polished mirror-bright in a chemical-mechanical process, in a first epitaxial growth phase. -
FIG. 2 illustrates a diagrammatic cross-section through thesemiconductor wafer 16 according toFIG. 1 following the completion of a first epitaxial growth phase. In this epitaxial growth phase, a thickness d of n-type silicon is grown in a monocrystalline manner; in this first embodiment of the invention, 20 to 80 atomic % of the doping material for drift zones are homogeneously distributed in this epitaxial layer. The missing doping material quantity of 80 to 20 atomic % can be introduced near the surface by ion implantation to limit the widening of the compensation regions by the lateral diffusion of the complementary-type doping materials for charge compensation zones. - This homogeneous pre-doping, which however only provides 20 to 80 atomic % of the doping materials of the drift zones, avoids the disadvantage of the relatively high resistance in the middle region of the epitaxial growth phase, which occurs in multiple epitaxial processes with non-doped epitaxial growth phases. In multiple epitaxial processes, a non-doped epitaxial layer is often applied, followed by the doping of the drift zones and the charge compensation zones by ion implantation. The pre-doping described above avoids such disadvantages of reduced conductivity in the middle of the epitaxial growth phase.
- The missing doping material balance between 80 and 20 atomic % can then be introduced near the surface by ion implantation as illustrated in
FIG. 3 , thereby limiting the lateral widening of the charge compensation columns. The on resistance is affected both by wide compensation regions and by insufficiently high doping in the middle of the epitaxial growth phases. By using simulations, it can be shown that the on resistance can be minimized by the combination of two methods described above, i.e. the doping of the epitaxy and implantation between the epitaxial growth phases. -
FIG. 3 illustrates a diagrammatic cross-section through thesemiconductor wafer 16 according toFIG. 2 following the ion implantation of a doping material balance Δn for a first conduction type. AsFIG. 3 illustrates, a charge carrier concentration of n+Δn is obtained near the surface of thefirst epitaxial layer 18 by an additional ion implantation of, for example, phosphorus or arsenic for afirst conduction type 4 of the drift zones. The near-surface zone with thedoping material balance 9 of 80 to 20 atomic % of drift zone doping as illustrated inFIG. 3 will in the subsequent diffusion process be distributed in the illustrated epitaxial layer to a thickness d. -
FIG. 4 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 3 following the selective ion implantation of acomplementary conduction type 7 inwindows 23 of a previously appliedion implantation mask 22 for the secondcomplementary conduction type 7. Boron may be used as a doping material for thecomplementary conduction type 7. As a concentration of doping material increased by Δn prevails near the surface in thedrift zone regions 3, the lateral expansion of the chargecompensation zone doping 8 in the subsequent diffusion process to form charge compensation zone columns or strips is limited, allowing for a smaller step size between the charge compensation zones and thus permitting a higher doping of the drift zones. -
FIG. 5 illustrates a diagrammatic cross-section through thesemiconductor wafer 16 according toFIG. 4 following a second epitaxial growth phase and an ion implantation of a doping material balance of the first conduction type, which is once again introduced into thissecond epitaxial layer 24 unmasked, over a large area and near the surface. This ion implantation of thefirst conduction type 4 for thedrift zone 3 does not require any diffusion mask for the near-surface introduction of thedoping material balance 9. Only the next process illustrated inFIG. 6 requires a suitableion implantation mask 22 for the selective introduction of a doping material of a complementary conduction type. -
FIG. 6 illustrates a diagrammatic cross-section through thesemiconductor wafer 16 according toFIG. 5 following the selective ion implantation of a doping material of a complementary second conduction type. This creates a further doping material reservoir in theopen windows 23 of theion implantation mask 22, but without any connection to the complementary-type regions of the charge compensation zones as illustrated inFIG. 4 . -
FIG. 7 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases, wherein 20 to 80 atomic % of homogeneously distributed doping material of thefirst conduction type 4 have been introduced and the missing doping material balance is introduced near the surface in theregions 9 by ion implantation after each epitaxial growth phase, resulting in the structure illustrated inFIG. 7 , wherein the selectively introduced chargecompensation zone doping 8 does not yet form a coherent charge compensation zone column or strip. This requires a further diffusion process, wherein thedoping material balance 9 for thedrift zones 3 is distributed further in the semiconductor material. -
FIG. 8 illustrates a diagrammatic cross-section through the section according toFIG. 7 following the diffusing together of the implanted charge compensation zone doping to form a column- or strip-shapedcharge compensation zone 6. Whether column- or strip-shapedcharge compensation zones 6 are generated depends on the ion implantation mask prepared for the semiconductor device. The doping material balance Δn has likewise been distributed further in thedrift zones 3 by diffusion processes, so that relatively highly dopeddrift zones 3 of a small step size p in micrometers of p≦12 μm can be created, which reduces the on resistance of a semiconductor device with a drift zone structure of this type. -
FIG. 9 illustrates a diagram with optimised concentration fluctuations of the doping material in a drift zone. The doping material concentration N is plotted on the abscissa, while the penetration depth, which is a measure for the blocking capability of the semiconductor device, is plotted on the ordinate. Compared to semiconductor devices with a non-doped epitaxy, where the maximum and minimum values fluctuate about twice as much, concentration fluctuations are noticeably minimized owing to the homogeneous pre-doping of the epitaxial layers in the range of 20 to 80 atomic %. - The homogeneously distributed proportion of doping material in the epitaxial growth phases can be limited to a third of the total concentration of doping material for the first conduction type, while two thirds subsequently have to be introduced near the surface by ion implantation. In this embodiment of the invention, it is on the other hand desirable that the proportion of doping material introduced by ion implantation is significantly larger than the proportion introduced into the semiconductor crystal by homogeneous doping in the epitaxial growth phase.
- Fluctuations in the concentration of doping material for the drift zones can be reduced further by using a technology and a manufacturing process described below with reference to
FIGS. 10 to 18 and resulting in a semiconductor device illustrated inFIG. 19 . This method is likewise based on asemiconductor wafer 16 as illustrated inFIG. 10 , which is highly doped with an n+-type doping material. -
FIG. 11 illustrates a diagrammatic cross-section through thesemiconductor wafer 16 according toFIG. 10 following the completion of a first epitaxial growth phase. In this epitaxial growth phase, however, the doping material is not introduced homogeneously, but rather inhomogeneously, i.e. the addition of doping material is reduced or stopped completely during the epitaxial growth process, resulting in a maximum of doping material approximately in the middle of the epitaxial growth phase. The boundaries of the region with a maximum doping nmax are indicated by dot-dash lines in theepitaxial layer 18 ofFIG. 11 . - In the subsequent ion implantation to introduce a doping material balance Δn, the relatively lightly doped, near-surface region is filled unmasked with the doping material balance over a large area by using ion implantation as illustrated in
FIG. 12 . -
FIG. 13 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 12 following the selective ion implantation of a doping material for a complementary second conduction type. ThisFIG. 13 corresponds toFIG. 4 , and owing to the ion-implanted concentration of doping material, the lateral outdiffusion of the p-type material introduced by ion implantation is limited, allowing the production of compensated semiconductor devices with small step sizes of less than 12 μm. -
FIG. 14 illustrates a diagrammatic cross-section through the semiconductor wafer according toFIG. 13 following a second epitaxial growth phase and an ion implantation of a doping material balance of a first conduction type, which is once again introduced unmasked and over a large area into the semiconductor wafer. Moreover, a maximum nmax of doping material is introduced in the middle of the growth phase during the second epitaxial growth phase, in order to increase the doping in the drift zone further and to ensure that the on resistance for a compensated device of this type is further reduced.FIG. 14 also indicates by a dot-dash line that the doping of the epitaxial layer is initially reduced towards the surface, but the missing doping material balance is then introduced by large-area ion implantation, resulting in a concentration which is capable of impeding a lateral outdiffusion for the charge compensation zones to be formed. -
FIG. 15 illustrates a diagrammatic cross-section through thesemiconductor wafer 16 according toFIG. 14 following the selective ion implantation of a doping material of a complementary second conduction type inwindows 23 of anion implantation mask 22, generating further p-type islands which are diffused together on completion of all of the epitaxial growth phases; in this process, the concentration of doping material in the drift zones becomes uniform. -
FIG. 16 illustrates a diagrammatic cross-section through a section of the semiconductor wafer following the completion of six epitaxial growth phases, wherein initially a maximum doping nmax of thefirst conduction type 4 is generated in each epitaxial growth phase, followed by the introduction of a doping material balance in the region of the future drift zones by large-area ion implantation. -
FIG. 17 illustrates a diagrammatic cross-section through the section according toFIG. 16 following the diffusing together of the implanted chargecompensation zone doping 8 to form a column- or strip-shapedcharge compensation zone 6. Thiscolumn 10 illustrates a reduced lateral outdiffusion between individual epitaxial growth phases, allowing for a smaller step size in combination with higher doping of thedrift zones 3. -
FIG. 18 illustrates further reduced fluctuations of the charge carrier concentration in the drift zone. The doping material concentration N is plotted on the abscissa, while the thickness or depth in the direction z of the individual epitaxial growth phases is once again plotted on the ordinate. The dot-dash line within each epitaxial growth phase indicates a maximum concentration of doping material introduced into each epitaxial layer, while ion implantation with a concentration of Δn is carried out between the epitaxial growth phases, which in turn prevents the lateral outdiffusion of the complementary-conducting material for the charge compensation zones. - The distribution of the charge carrier concentration Δn introduced by ion implantation is indicated by broken lines, while the fluctuation of the charge carrier concentration in the drift zones after diffusion is indicated by a continuous line. Any fluctuations which are still noticeable are so negligible that the charge compensation zones and the drift zones can come closer together, allowing for a higher drift zone doping.
-
FIG. 19 illustrates a diagrammatic cross-section through asemiconductor device 1 according to an embodiment wherein the lateral outdiffusion for thecharge compensation zones 6 is significantly reduced by the methods described above, whereby the fluctuation of the doping material concentration in the drift zones is reduced in the vertical direction. This embodiment is a vertical MOSFET with a lateral gate structure, but the teaching of the invention can also be applied to JFET or other compensated device structures, provided that a multiple epitaxial structure is provided for the drift zone. - In this embodiment, the charge compensation zones are completed by the near-surface introduction of a p-
type body zone 12, which in turn accommodates a highly doped n+-type source zone 13, wherein the highly doped n+-type source zone 13 and thebody zone 12 are contacted by ametallic source electrode 14, while a lateral gate structure insulated against thebody zone 12 by agate oxide 25 permits the control of this power transistor. As a result of the negligible lateral bulging of the charge compensation zones, astep size 15 of less than 12 μm can be achieved between the charge compensation zones. - Before the
back side 21 of thesemiconductor body 2 is metallised for a drain D, thesubstrate 17 or theoriginal semiconductor wafer 16 can be ground thin, thus further minimising the on resistance of thesemiconductor device 1. - Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.
Claims (25)
1. A semiconductor device with a semiconductor body, comprising:
drift zones of a first conduction type comprising epitaxially grown semiconductor material,
charge compensation zones of a second conduction type complementary to the first conduction type, which are arranged laterally adjacent to the drift zones and comprise a laterally limited charge compensation zone doping, which is introduced into the epitaxially grown semiconductor material;
the epitaxially grown semiconductor material comprising 20 to 80 atomic % of the doping material of the drift zones distributed in the epitaxially grown semiconductor material and a doping material balance between 80 and 20 atomic % introduced by ion implantation and diffusion.
2. The semiconductor device of claim 1 , wherein the epitaxially grown semiconductor material comprises 20 to 80 atomic % of the doping material of the drift zones homogeneously distributed in the epitaxially grown semiconductor material.
3. The semiconductor device of claim 1 , wherein the epitaxially grown semiconductor material is applied in epitaxial growth phases and 20 to 80 atomic % of the doping material of the drift zones are inhomogeneously distributed in the epitaxially grown semiconductor material such that a minimum of the concentration of doping material is located in a middle region of an individual epitaxial growth phase.
4. The semiconductor device of claim 1 , wherein the doping material balance of 80 to 20 atomic % introduced by ion implantation and diffusion has a maximum concentration of doping material at the end of an individual epitaxial growth phase.
5. The semiconductor device of claim 1 , wherein the concentration of the doping material balance introduced by ion implantation and diffusion is higher than the concentration of the doping material of the epitaxially grown semiconductor material.
6. The semiconductor device of claim 1 , wherein the concentration of the doping material balance introduced by ion implantation and diffusion comprises nearly two thirds of the total concentration of the doping material of the drift zones.
7. The semiconductor device of claim 1 , wherein the doping material balance for drift zones is introduced over a large area and unmasked into the epitaxially grown semiconductor material.
8. The semiconductor device of claim 1 , wherein the charge compensation zones comprise column- or strip-shaped regions introduced by masked ion implantation and diffusion in the epitaxially grown semiconductor material.
9. The semiconductor device of claim 1 , wherein the semiconductor device comprises a near-surface body zone with a doping complementary to the first conduction type, in which there is located a source zone of the first conduction type, which is doped more highly than the drift section and which is contacted by a metallic source electrode similar to the body zone.
10. The semiconductor device of claim 1 , wherein the laterally integrated doping material dose CD in the drift zones or the charge compensation zones is less than twice the breakdown charge of silicon.
11. The semiconductor device of claim 1 , wherein the laterally integrated doping material dose CD in the drift zones or the charge compensation zones is less than twice the breakdown charge CL at a typical doping and CD≦2 CL of silicon with CD=3×1012 cm2.
12. The semiconductor device of claim 1 , wherein the charge compensation zones are arranged at a process size p, the process size p in micrometers being p≦12 μm.
13. A method for the production of a semiconductor device with a semiconductor body having drift zones of a first conduction type and charge compensation zones of a complementary conduction type, the method comprising:
a) providing a semiconductor wafer as a semiconductor substrate;
b) applying an epitaxial layer in a first epitaxial growth phase, during which the semiconductor material is in the process of epitaxial growth doped on the semiconductor wafer with 20 to 80 atomic % of a doping material of the first conduction type;
c) unmasked ion implantation of doping material of the first conduction type for the near-surface introduction of a doping material balance of 80 to 20 atomic % into the epitaxial layer;
d) masked ion implantation for a charge compensation zone structure with a doping complementary to the drift zone;
e) repeating steps b) to d) until a predetermined epitaxial layer thickness is reached;
f) indiffusing of the doping materials for the drift zones and the charge compensation zones until coherent charge compensation zones are generated;
g) completing of a semiconductor chip structure for power semiconductor devices on the semiconductor wafer.
14. The method of claim 13 , wherein the doping with 20 to 80 atomic % of the doping material of the first conduction type is carried out with homogeneous distribution during the application of the epitaxial layer in the epitaxial growth phase.
15. The method of claim 13 , wherein the doping with 20 to 80 atomic % of the doping material of the first conduction type is carried out with inhomogeneous distribution during the application of the epitaxial layer in the epitaxially grown semiconductor material in such a way that a maximum of the concentration of doping material is introduced into the semiconductor material in a middle region of an individual epitaxial growth phase.
16. The method of claim 13 , wherein the thickness of the individual epitaxial layers per repetition step is increased compared to conventional techniques and the number of repetition steps is reduced accordingly.
17. The method of claim 13 , wherein a doping material balance for the first conduction type, the concentration of which is higher than the concentration of the already homogeneously distributed doping material of the epitaxially grown semiconductor material, is introduced by ion implantation and diffusion.
18. The method of claim 13 , wherein a doping material balance with a concentration comprising nearly two thirds of the total concentration of doping material of the drift zones is introduced near the surface by using ion implantation and diffusion.
19. The method of claim 13 , wherein a doping material balance for drift zones is introduced over a large area and unmasked into the epitaxially grown semiconductor material by ion implantation and diffusion.
20. The method of claim 13 , wherein the charge compensation zones are introduced in column- or strip-shaped regions into the epitaxially grown semiconductor material by masked ion implantation and diffusion.
21. The method of claim 13 , wherein body zones with a doping complementary to the first conduction type are introduced near the surface into the epitaxially grown semiconductor material, wherein source zones of the first conduction type with a higher doping than the drift zones are introduced into the body zones, and wherein contact holes are then produced through an insulating layer up to the source zones and the body zones, to which a conductive source electrode structure is subsequently applied.
22. The method of claim 13 , wherein the introduction of the doping materials provides a doping material dose CD in the drift zones and into the charge compensation zones which is less than the breakdown charge CL with CD≦CL of silicon with CL=2×1012 cm−2.
23. The method of claim 13 , wherein the charge compensation zones are arranged at a step size p in micrometers, with p≦11 μm.
24. The method of claim 13 , wherein, within the epitaxially grown semiconductor material, the homogeneously distributed concentration of the doping material of the drift zones never falls below the set value at any time during production.
25. The method of claim 13 , wherein the completion of the semiconductor chip structures for power semiconductor devices on the semiconductor wafer is followed by the thinning of the semiconductor substrate and by its cutting into semiconductor chips.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/052,019 US20090236680A1 (en) | 2008-03-20 | 2008-03-20 | Semiconductor device with a semiconductor body and method for its production |
DE102009010373.2A DE102009010373B4 (en) | 2008-03-20 | 2009-02-26 | Method for producing a semiconductor component with a semiconductor body |
US13/085,196 US8569150B2 (en) | 2008-03-20 | 2011-04-12 | Method for producing a semiconductor device with a semiconductor body |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/052,019 US20090236680A1 (en) | 2008-03-20 | 2008-03-20 | Semiconductor device with a semiconductor body and method for its production |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/085,196 Division US8569150B2 (en) | 2008-03-20 | 2011-04-12 | Method for producing a semiconductor device with a semiconductor body |
Publications (1)
Publication Number | Publication Date |
---|---|
US20090236680A1 true US20090236680A1 (en) | 2009-09-24 |
Family
ID=41088017
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/052,019 Abandoned US20090236680A1 (en) | 2008-03-20 | 2008-03-20 | Semiconductor device with a semiconductor body and method for its production |
US13/085,196 Active 2028-04-27 US8569150B2 (en) | 2008-03-20 | 2011-04-12 | Method for producing a semiconductor device with a semiconductor body |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/085,196 Active 2028-04-27 US8569150B2 (en) | 2008-03-20 | 2011-04-12 | Method for producing a semiconductor device with a semiconductor body |
Country Status (2)
Country | Link |
---|---|
US (2) | US20090236680A1 (en) |
DE (1) | DE102009010373B4 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102800701A (en) * | 2011-05-25 | 2012-11-28 | 快捷韩国半导体有限公司 | Semiconductor device having a super junction structure and method of manufacturing the same |
CN103022123A (en) * | 2011-09-21 | 2013-04-03 | 上海华虹Nec电子有限公司 | Super junction semiconductor device and manufacturing method thereof |
CN103021863A (en) * | 2011-09-27 | 2013-04-03 | 万国半导体股份有限公司 | Manufacturing methods for accurately aligned and self-balanced superjunction devices |
CN104009072A (en) * | 2013-02-25 | 2014-08-27 | 中国科学院微电子研究所 | Insulated gate bipolar transistor and manufacturing method |
CN105225959A (en) * | 2014-07-01 | 2016-01-06 | 北大方正集团有限公司 | The manufacture method of slot type power device and slot type power device |
US9647059B2 (en) | 2011-09-27 | 2017-05-09 | Alpha And Omega Semiconductor Incorporated | Manufacturing methods for accurately aligned and self-balanced superjunction devices |
CN112820628A (en) * | 2020-12-31 | 2021-05-18 | 广州粤芯半导体技术有限公司 | Method for preparing epitaxial layer |
US20220271154A1 (en) * | 2021-02-25 | 2022-08-25 | Db Hitek Co., Ltd. | Superjunction semiconductor device and method of manufacturing same |
WO2023216648A1 (en) * | 2022-05-09 | 2023-11-16 | 瑶芯微电子科技(上海)有限公司 | Method for improving epitaxial growth stability of super-junction structure and preparing semiconductor device |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9583578B2 (en) * | 2013-01-31 | 2017-02-28 | Infineon Technologies Ag | Semiconductor device including an edge area and method of manufacturing a semiconductor device |
US9564515B2 (en) | 2014-07-28 | 2017-02-07 | Taiwan Semiconductor Manufacturing Co., Ltd. | Semiconductor device having super junction structure and method for manufacturing the same |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6551909B1 (en) * | 1998-07-24 | 2003-04-22 | Fuji Electric Co. Ltd. | Semiconductor device with alternating conductivity type layer and method of manufacturing the same |
US20030122222A1 (en) * | 2001-12-27 | 2003-07-03 | Hideki Okumura | Semiconductor device having vertical metal insulator semiconductor transistor and method of manufacturing the same |
US6667514B2 (en) * | 2001-07-03 | 2003-12-23 | Infineon Technologies Ag | Semiconductor component with a charge compensation structure and associated fabrication |
US6878989B2 (en) * | 2001-05-25 | 2005-04-12 | Kabushiki Kaisha Toshiba | Power MOSFET semiconductor device and method of manufacturing the same |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1668688A4 (en) * | 2003-09-19 | 2011-03-02 | Tinggi Technologies Private Ltd | Fabrication of semiconductor devices |
DE102006004627B3 (en) | 2005-10-24 | 2007-04-12 | Infineon Technologies Austria Ag | Power semiconductor device with charge compensation structure and method for producing the same |
-
2008
- 2008-03-20 US US12/052,019 patent/US20090236680A1/en not_active Abandoned
-
2009
- 2009-02-26 DE DE102009010373.2A patent/DE102009010373B4/en active Active
-
2011
- 2011-04-12 US US13/085,196 patent/US8569150B2/en active Active
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6551909B1 (en) * | 1998-07-24 | 2003-04-22 | Fuji Electric Co. Ltd. | Semiconductor device with alternating conductivity type layer and method of manufacturing the same |
US6878989B2 (en) * | 2001-05-25 | 2005-04-12 | Kabushiki Kaisha Toshiba | Power MOSFET semiconductor device and method of manufacturing the same |
US6667514B2 (en) * | 2001-07-03 | 2003-12-23 | Infineon Technologies Ag | Semiconductor component with a charge compensation structure and associated fabrication |
US20030122222A1 (en) * | 2001-12-27 | 2003-07-03 | Hideki Okumura | Semiconductor device having vertical metal insulator semiconductor transistor and method of manufacturing the same |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102800701A (en) * | 2011-05-25 | 2012-11-28 | 快捷韩国半导体有限公司 | Semiconductor device having a super junction structure and method of manufacturing the same |
US11133379B2 (en) * | 2011-05-25 | 2021-09-28 | Semiconductor Components Industries, Llc | Semiconductor device having a super junction structure and method of manufacturing the same |
US11588016B2 (en) | 2011-05-25 | 2023-02-21 | Semiconductor Components Industries, Llc | Semiconductor device having a super junction structure and method of manufacturing the same |
CN103022123A (en) * | 2011-09-21 | 2013-04-03 | 上海华虹Nec电子有限公司 | Super junction semiconductor device and manufacturing method thereof |
CN103021863A (en) * | 2011-09-27 | 2013-04-03 | 万国半导体股份有限公司 | Manufacturing methods for accurately aligned and self-balanced superjunction devices |
US9647059B2 (en) | 2011-09-27 | 2017-05-09 | Alpha And Omega Semiconductor Incorporated | Manufacturing methods for accurately aligned and self-balanced superjunction devices |
CN104009072A (en) * | 2013-02-25 | 2014-08-27 | 中国科学院微电子研究所 | Insulated gate bipolar transistor and manufacturing method |
CN105225959A (en) * | 2014-07-01 | 2016-01-06 | 北大方正集团有限公司 | The manufacture method of slot type power device and slot type power device |
CN112820628A (en) * | 2020-12-31 | 2021-05-18 | 广州粤芯半导体技术有限公司 | Method for preparing epitaxial layer |
US20220271154A1 (en) * | 2021-02-25 | 2022-08-25 | Db Hitek Co., Ltd. | Superjunction semiconductor device and method of manufacturing same |
US12009419B2 (en) * | 2021-02-25 | 2024-06-11 | DB HiTek, Co., Ltd. | Superjunction semiconductor device and method of manufacturing same |
WO2023216648A1 (en) * | 2022-05-09 | 2023-11-16 | 瑶芯微电子科技(上海)有限公司 | Method for improving epitaxial growth stability of super-junction structure and preparing semiconductor device |
Also Published As
Publication number | Publication date |
---|---|
US20110189839A1 (en) | 2011-08-04 |
US8569150B2 (en) | 2013-10-29 |
DE102009010373B4 (en) | 2016-11-17 |
DE102009010373A1 (en) | 2009-11-05 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8569150B2 (en) | Method for producing a semiconductor device with a semiconductor body | |
US9024329B2 (en) | Silicon carbide trench MOSFET having reduced on-resistance, increased dielectric withstand voltage, and reduced threshold voltage | |
US6979862B2 (en) | Trench MOSFET superjunction structure and method to manufacture | |
US7598143B2 (en) | Method for producing an integrated circuit with a trench transistor structure | |
US7968919B2 (en) | Integrated circuit including a charge compensation component | |
US20010041400A1 (en) | Angle implant process for cellular deep trench sidewall doping | |
US7049658B2 (en) | Power semiconductor device | |
US9006062B2 (en) | Method of manufacturing a semiconductor device including an edge area | |
JPS59167066A (en) | Vertical type metal oxide semiconductor field effect transistor | |
US20170288047A1 (en) | Shallow-Trench Semi-Super-Junction VDMOS Device and Manufacturing Method Therefor | |
CN106252414A (en) | There is the transistor of the avalanche breakdown behavior of field plate and improvement | |
JP5319918B2 (en) | Method for forming wafer used for high voltage semiconductor device and wafer used for high voltage semiconductor device | |
US6969657B2 (en) | Superjunction device and method of manufacture therefor | |
CN101567384A (en) | High voltage power MOSFET having low on-resistance | |
US11764296B2 (en) | Method for manufacturing a semiconductor device | |
KR19990023121A (en) | Semiconductor device and manufacturing method thereof | |
KR101315699B1 (en) | Power mosfet having superjunction trench and fabrication method thereof | |
TWI405879B (en) | Semiconductor wafer suitable for forming a semiconductor junction diode device and method of forming same | |
JP2006140250A (en) | Semiconductor device and manufacturing method thereof | |
CN107039243B (en) | Super junction device and manufacturing method thereof | |
KR101887910B1 (en) | SiC MOSPET power semiconductor device and method of fabricating the same | |
CN109192659A (en) | A kind of production method of depletion field effect transistor | |
JPH07147399A (en) | Semiconductor device | |
CN114597264A (en) | Power MOSFET device and manufacturing method thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: INFINEON TECHNOLOGIES AUSTRIA AG, AUSTRIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WILLMEROTH, ARMIN;HIRLER, FRANZ;REEL/FRAME:021049/0555 Effective date: 20080331 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |