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
  • H01L29/7813—Vertical DMOS transistors, i.e. VDMOS transistors with trench gate electrode, e.g. UMOS 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
  • H01L29/66—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
  • H01L29/7803—Vertical DMOS transistors, i.e. VDMOS transistors structurally associated with at least one other device
  • H01L29/7806—Vertical DMOS transistors, i.e. VDMOS transistors structurally associated with at least one other device the other device being a Schottky barrier diode
• • 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
  • H01L29/86—Types of semiconductor device ; Multistep manufacturing processes therefor controllable only by variation of the electric current supplied, or only the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched
  • H01L29/861—Diodes
  • H01L29/872—Schottky diodes
• • 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
  • H01L29/86—Types of semiconductor device ; Multistep manufacturing processes therefor controllable only by variation of the electric current supplied, or only the electric potential applied, to one or more of the electrodes carrying the current to be rectified, amplified, oscillated or switched
  • H01L29/861—Diodes
  • H01L29/872—Schottky diodes
  • H01L29/8725—Schottky diodes of the trench MOS barrier type [TMBS]
• • 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
  • H01L21/22—Diffusion of impurity materials, e.g. doping materials, electrode materials, into or out of a semiconductor body, or between semiconductor regions; Interactions between two or more impurities; Redistribution of impurities
  • H01L21/223—Diffusion of impurity materials, e.g. doping materials, electrode materials, into or out of a semiconductor body, or between semiconductor regions; Interactions between two or more impurities; Redistribution of impurities using diffusion into or out of a solid from or into a gaseous phase
• • 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
  • H01L29/04—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their crystalline structure, e.g. polycrystalline, cubic or particular orientation of crystalline planes
• • 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]
  • H01L29/0619—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] with a supplementary region doped oppositely to or in rectifying contact with the semiconductor containing or contacting region, e.g. guard rings with PN or Schottky junction
• • 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
  • H01L29/66—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
  • H01L29/66734—Vertical DMOS transistors, i.e. VDMOS transistors with a step of recessing the gate electrode, e.g. to form a trench gate electrode

Definitions

• the invention relates to a semiconductor device, in particular a
• Power semiconductor device especially a power MOS field effect transistor with integrated Trench Junction Barrier Schottky (TJBS) diode.
• TJBS Trench Junction Barrier Schottky
• Such a power semiconductor component can be used for example in synchronous rectifiers for generators in motor vehicles.
• Power MOS field effect transistors have been used for decades as fast switches for power electronics applications.
• DMOS double-diffused structures
• TrenchMOS trench structures
• MOSFETs with trench structures are also used.
• MOSFETs with very fast switching operations in which current flows over the body diode of the MOSFET for a short time, z.
• a parallel connection of MOSFET e.g. proposed with its integrated pn body diode and a Schottky diode.
• Fig.l shows a simplified cross section of an arrangement of a Trench MOS with integrated MOS barrier Schottky diode (TMBS).
• An n-doped silicon layer 2 (epi layer), into which a multiplicity of trenches 3 are introduced, is located on a highly n + -doped silicon substrate 1.
• the interior of the trenches with a conductive material 5, z. B. with doped polysilicon filled.
• p-well p - doped layer
• a conventional, solderable metal system 11 z. B. from a layer sequence, Cr, NiV and Ag applied.
• the metal system 11 serves as a drain contact.
• Polysilizum Anlagenen 5 are electrically connected to each other and with a not shown gate contact.
• the Schottky diode is thus the regions in which the metal layer 9 contacts the n-doped silicon 2, connected in parallel to the body diode of the MOSFET, that is to say the p-doped layer 6 and n-doped layer 2. Becomes When reverse voltage is applied, space charge zones form between the trench structures adjacent to the Schottky contacts and shield the electric field from the actual Schottky contacts, that is, the transition 9-2. Due to the smaller field at the Schottky contact, the BL effect is reduced, ie a blocking current increase with increasing blocking voltage is prevented. As a result of the lower forward voltage of the Schottky diode, the pn body diode is not operated in the direction of flow. As the inverse diode of the MOSFET, therefore, the Schottky diode 9-2 acts.
• Breakthroughs of the NPN structure come. This operation is therefore i. a. not allowed.
• such an operation is possible in principle, but not recommended for quality reasons because of the then occurring charge carrier injection into the MOS structure of the TMBS.
• junction barrier Schottky diodes are planar Schottky diodes in which flat regions are diffused with opposite conductivity type to the substrate doping, e.g. B. p-doped regions in n-doped substrate. When blocking voltage is applied, the space charge zones grow between the p-doped regions
• TJBS diodes Trench MOS Barrier Schottky
• the breakdown voltage of the TJBS structure can be greater or smaller than the breakdown voltage of the - still existing PN Bodydiode - are selected.
• Avalanche breakdown voltage (Z voltage) of the TJBS structure is smaller than the breakdown voltage of the NPN transistor or the pn body diode, the device can be operated even at higher currents in the breakdown.
• Fig. 1 Schematic, fragmentary cross section of a power trench MOS field effect transistor with integrated TMBS diode according to the prior art.
• Fig. 2 Schematic, fragmentary cross section of a first
• Fig. 3 Schematic, partially shown cross-section of a second arrangement according to the invention.
• Fig. 4 Schematic, partially shown cross section of a further inventive arrangement.
• Fig. 5 Schematic cross-section of a further inventive arrangement with integrated TJBS structures shown.
• a first embodiment of the invention is shown schematically and partially in cross section. This is a
• n-doped silicon layer for example an epi-layer 2, into which a multiplicity of trenches 3 are introduced, is located on a highly n + -doped silicon substrate 1.
• Most trenches are in turn provided on the sidewalls and at the bottom with a thin, mostly made of silicon dioxide, dielectric layer 4.
• the interior is again with a conductive material 5, z. B. with doped polysilicon filled.
• the polysilicon layers 5 are galvanically connected to one another and to a gate contact (not shown).
• p - well Between these trenches there is a p - doped layer (p - well) 6. In this p - doped layer are on the surface highly n + doped regions 8 (source) and highly p + - doped regions 7, for connecting the p - well serve, introduced. At some areas of the component there is no p - doped layer (p - well) 6 between the trenches, but only the n - doped epilayer 2. These trenches are also not with a
• Silicon dioxide layer 4 but with p-doped silicon or
• the trenches are either completely filled in, as shown in FIG. 2, or may cover only the surface of the trench walls and floors. At the top, these p-doped regions with highly p + doped silicon over the entire surface or only partially be doped to a better ohmic
• the depth of the trenches is approximately 1 - 3 ⁇ m for a (20-4O) VoIt component, and the distance between the trenches, the mesa area, is then typically less than 0.5 micrometers. Of course, the dimensions are not limited to these values.
• So z. B. at higher blocking MOSFETs preferably selected deeper trenches and wider Mesa withe.
• the well-known p-doped layer (p-well) 6 adjoins the outermost trench filled with p-doped material. However, in the section up to the next trench filled with silicon dioxide 4 and polysilicon 5, there are in each case no highly n + -doped regions 8 and in most cases no highly p + -doped regions 7.
• Region I represents a so-called trench-junction barrier Schottky diode (TJBS).
• TJBS trench-junction barrier Schottky diode
• the breakdown voltage is also smaller than the breakdown voltage of the pn inverse diode 6-2 or the
• Breakdown voltage of the parasitic NPN transistor composed of the areas 8, (7,6) and 2.
• conductive layer 9 is as in the case of Fig. 1 i. a. again a thicker, conductive metal layer, or a layer system of several
• Fig. 3 is another embodiment of an inventive
• the inner trenches, the trenches of the TJBS, are not filled with p-doped silicon or polysilicon but are completely or partially filled with metal.
• the areas 13 may, for. B. using a Diboran gas phase occupancy followed by diffusion or baking step z. B. Rapid Thermal Annealing RTP generated. Doping and diffusion or annealing step are chosen so that the corresponding breakdown voltage UZ_TJBS is achieved. All other variants of the arrangements according to the invention can optionally be carried out with p-doped silicon or polysilicon filled trenches 12.
• FIG. 4 shows a further variant of an arrangement according to the invention.
• the trenches of the TJBS face trenches with a gate structure. If the MOSFET is to be operated in the breakthrough, the MOSFET is to be operated in the breakthrough, the MOSFET is to be operated in the breakthrough, the
• the outermost trench structures of the TJBS are either in contact with the body region 6, as shown in FIGS. 2 and 3, or they are arranged opposite to the MOS trench structures as in FIG.
• the trenches or trenches of the TJBS can also be located at a certain distance, as shown in FIG. 5, between p-doped body regions 6.
• the TJBS structures can be located in the interior of the MOSFET chip, or arranged on the edge of the chip.

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)
• Electrodes Of Semiconductors (AREA)
• Metal-Oxide And Bipolar Metal-Oxide Semiconductor Integrated Circuits (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42272571

Family Applications (1)

Country Status (7)

Families Citing this family (12)

Citations (1)

Family Cites Families (11)

• 2009
  • 2009-08-05 DE DE102009028240A patent/DE102009028240A1/de not_active Withdrawn
• 2010
  • 2010-06-10 WO PCT/EP2010/058166 patent/WO2011015397A1/de active Application Filing
  • 2010-06-10 US US13/388,738 patent/US20120187498A1/en not_active Abandoned
  • 2010-06-10 CN CN2010800345562A patent/CN102473725A/zh active Pending
  • 2010-06-10 JP JP2012523255A patent/JP2013501367A/ja active Pending
  • 2010-06-10 EP EP10721527A patent/EP2462618A1/de not_active Withdrawn
  • 2010-08-03 TW TW099125667A patent/TW201108394A/zh unknown

Patent Citations (1)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events