US20180308964A1 - Semiconductor device - Google Patents
Semiconductor device Download PDFInfo
- Publication number
- US20180308964A1 US20180308964A1 US16/019,047 US201816019047A US2018308964A1 US 20180308964 A1 US20180308964 A1 US 20180308964A1 US 201816019047 A US201816019047 A US 201816019047A US 2018308964 A1 US2018308964 A1 US 2018308964A1
- Authority
- US
- United States
- Prior art keywords
- layer
- embedded
- binpl
- semiconductor device
- base substrate
- 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 description 57
- 239000000758 substrate Substances 0.000 claims abstract description 91
- 239000012535 impurity Substances 0.000 claims abstract description 61
- 239000004020 conductor Substances 0.000 claims 1
- 239000010410 layer Substances 0.000 description 139
- 238000009792 diffusion process Methods 0.000 description 17
- 238000002955 isolation Methods 0.000 description 17
- 239000011229 interlayer Substances 0.000 description 16
- 238000010438 heat treatment Methods 0.000 description 14
- 238000000034 method Methods 0.000 description 14
- 238000009826 distribution Methods 0.000 description 12
- 239000002344 surface layer Substances 0.000 description 8
- 101100332235 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) DRN1 gene Proteins 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 7
- 230000002542 deteriorative effect Effects 0.000 description 5
- 230000002401 inhibitory effect Effects 0.000 description 5
- 238000005468 ion implantation Methods 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- 101150024306 sou1 gene Proteins 0.000 description 4
- 101100168116 Magnaporthe oryzae (strain 70-15 / ATCC MYA-4617 / FGSC 8958) CON7 gene Proteins 0.000 description 3
- 101100168115 Neurospora crassa (strain ATCC 24698 / 74-OR23-1A / CBS 708.71 / DSM 1257 / FGSC 987) con-6 gene Proteins 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- 101100149883 Candida albicans (strain SC5314 / ATCC MYA-2876) SOU2 gene Proteins 0.000 description 2
- 101000830956 Homo sapiens Three-prime repair exonuclease 1 Proteins 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 102100024855 Three-prime repair exonuclease 1 Human genes 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- WURBVZBTWMNKQT-UHFFFAOYSA-N 1-(4-chlorophenoxy)-3,3-dimethyl-1-(1,2,4-triazol-1-yl)butan-2-one Chemical compound C1=NC=NN1C(C(=O)C(C)(C)C)OC1=CC=C(Cl)C=C1 WURBVZBTWMNKQT-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 239000000126 substance Substances 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
- H01L29/70—Bipolar devices
- H01L29/72—Transistor-type devices, i.e. able to continuously respond to applied control signals
- H01L29/739—Transistor-type devices, i.e. able to continuously respond to applied control signals controlled by field-effect, e.g. bipolar static induction transistors [BSIT]
- H01L29/7393—Insulated gate bipolar mode transistors, i.e. IGBT; IGT; COMFET
- H01L29/7395—Vertical transistors, e.g. vertical IGBT
- H01L29/7396—Vertical transistors, e.g. vertical IGBT with a non planar surface, e.g. with a non planar gate or with a trench or recess or pillar in the surface of the emitter, base or collector region for improving current density or short circuiting the emitter and base regions
- H01L29/7397—Vertical transistors, e.g. vertical IGBT with a non planar surface, e.g. with a non planar gate or with a trench or recess or pillar in the surface of the emitter, base or collector region for improving current density or short circuiting the emitter and base regions and a gate structure lying on a slanted or vertical surface or formed in a groove, e.g. trench gate IGBT
-
- 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
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/77—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate
- H01L21/78—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices
- H01L21/82—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices to produce devices, e.g. integrated circuits, each consisting of a plurality of components
- H01L21/822—Manufacture or treatment of devices consisting of a plurality of solid state components or integrated circuits formed in, or on, a common substrate with subsequent division of the substrate into plural individual devices to produce devices, e.g. integrated circuits, each consisting of a plurality of components the substrate being a semiconductor, using silicon technology
- H01L21/8232—Field-effect technology
- H01L21/8234—MIS technology, i.e. integration processes of field effect transistors of the conductor-insulator-semiconductor type
- H01L21/8238—Complementary field-effect transistors, e.g. CMOS
- H01L21/823892—Complementary field-effect transistors, e.g. CMOS with a particular manufacturing method of the wells or tubs, e.g. twin tubs, high energy well implants, buried implanted layers for lateral isolation [BILLI]
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
- H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body
- H01L27/08—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind
- H01L27/085—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only
- H01L27/088—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only the components being field-effect transistors with insulated gate
- H01L27/092—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body including only semiconductor components of a single kind including field-effect components only the components being field-effect transistors with insulated gate complementary MIS field-effect transistors
- H01L27/0922—Combination of complementary transistors having a different structure, e.g. stacked CMOS, high-voltage and low-voltage CMOS
-
- 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
Definitions
- the present invention relates to a semiconductor device and is, for example, a technology applicable to a semiconductor device having a diffusion layer embedded into a substrate.
- a diffusion layer is embedded into a substrate and a transistor is formed over the diffusion layer.
- a substance formed by epitaxially growing a semiconductor layer over a semiconductor substrate acting as a base is used as the substrate for example.
- the diffusion layer is: formed by an ion implantation method after the semiconductor layer is formed in some cases; or formed when the semiconductor layer is epitaxially grown in other cases.
- Japanese Unexamined Patent Application Publication No. Sho 62 (1987)-40719 describes that p-type impurities are diffused over the surface of a p-type substrate acting as a base by a thermal diffusion method and successively an epitaxial layer is grown over the substrate.
- Japanese Unexamined Patent Application Publication No. 2002-176177 describes that a semiconductor substrate is formed by forming an n-type epitaxial layer over the surface of a p-type substrate acting as a base and a trench gate type IGBT is formed by using the semiconductor substrate.
- the epitaxial layer has a configuration formed by stacking a low-concentration n-type layer over a high-concentration n-type layer.
- a first electrically conductive type semiconductor layer is formed over a first electrically conductive type base substrate.
- the impurity concentration of the semiconductor layer is lower than that of the base substrate.
- a second electrically conductive type first embedded layer and a second electrically conductive type second embedded layer are formed in the semiconductor layer.
- the second embedded layer is deeper than the first embedded layer, is kept away from the first embedded layer, and has an impurity concentration lower than the first embedded layer.
- a transistor is further formed in the semiconductor layer.
- the embodiment it is possible to inhibit: impurities from diffusing from the substrate to the semiconductor layer; and the withstand voltage of the transistor from deteriorating.
- FIG. 1 is a sectional view showing the configuration of a semiconductor device according to First Embodiment.
- FIG. 2 is a plan view of a transistor.
- FIG. 3 is a sectional view showing a manufacturing method of a semiconductor device.
- FIG. 4 is a sectional view showing the manufacturing method of the semiconductor device.
- FIG. 5 is a sectional view showing the manufacturing method of the semiconductor device.
- FIGS. 6A and 6B are views for explaining the distribution of impurities in the depth direction of a substrate.
- FIGS. 7A and 7B are sectional views showing a manufacturing method of a semiconductor device according to Second Embodiment.
- FIGS. 8A and 8B are views for explaining the distribution of impurities in the depth direction of a substrate.
- FIG. 9 is a sectional view showing the configuration of a semiconductor device according to Third Embodiment.
- FIGS. 10A and 10B are views for explaining the distribution of impurities in the depth direction of a substrate.
- FIG. 11 is a sectional view showing the configuration of a semiconductor device according to Fourth Embodiment.
- FIG. 1 is a sectional view showing the configuration of a semiconductor device SD according to First Embodiment.
- the semiconductor device SD according to the present embodiment is formed by using a substrate SUB.
- the substrate SUB is formed by growing an epitaxial layer EPI (semiconductor layer) comprising a semiconductor (for example silicon) over a base substrate BSUB comprising a bulk semiconductor (for example monocrystal silicon).
- EPI semiconductor layer
- Both the base substrate BSUB and the epitaxial layer EPI are an identical electrically conductive type (first electrically conductive type: for example P-type).
- the impurity concentration of the base substrate BSUB is higher than that of the epitaxial layer EPI.
- a first embedded layer BINPL 1 that is an electrically conductive type (second electrically conductive type: for example n-type) different from the epitaxial layer EPI is formed in the epitaxial layer EPI.
- the first embedded layer BINPL 1 is kept away from the base substrate BSUB.
- the first embedded layer BINPL 1 either may be formed when the epitaxial layer EPI is grown epitaxially; or may be formed by an ion implantation method after the epitaxial layer EPI is formed. In the former case, the first embedded layer BINPL 1 is formed over the whole surface of the substrate SUB.
- a second embedded layer BINPL 2 is formed in the epitaxial layer EPI.
- the second embedded layer BINPL 2 is a second electrically conductive type impurity layer, is deeper than the first embedded layer BINPL 1 , and is kept away from the first embedded layer BINPL 1 .
- the impurity concentration of the second embedded layer BINPL 2 is lower than that of the first embedded layer BINPL 1 .
- the second embedded layer BINPL 2 is formed in order to inhibit: the impurities of the base substrate BSUB from diffusing in the epitaxial layer EPI; and the first electrically conductive type impurity concentration in the lower layer of the epitaxial layer EPI from increasing.
- transistors TR 2 and TR 3 constituting a logic circuit and a transistor TR 1 for electric power control are formed in the epitaxial layer EPI. At least the transistor TR 1 overlaps with the first embedded layer BINPL 1 in a planar view.
- first electrically conductive type is a p-type and the second electrically conductive type is an n-type. It is also possible however that the first electrically conductive type is an n-type and the second electrically conductive type is a p-type.
- the transistor TR 2 is an n-type low withstand voltage transistor and has a gate electrode GE 2 , a source SOU 2 , and a drain DRN 2 .
- the transistor TR 3 is a p-type low withstand voltage transistor and has a gate electrode GE 3 , a source SOU 3 , and a drain DRN 3 .
- the transistors TR 2 and TR 3 include a CMOS transistor. Meanwhile, a gate insulating film (not shown in the figure) is formed under the gate electrodes GE 2 and GE 3 .
- the transistor TR 1 is a horizontal transistor for electric power control and has a withstand voltage higher than the transistors TR 2 and TR 3 .
- the transistor TR 1 has a gate electrode GE 1 , a source SOU 1 , and a drain DRN 1 .
- the distance between the drain DRN 1 and the gate electrode GE 1 is larger than the distance between the source SOU 1 and the gate electrode GE 1 .
- the withstand voltage between the drain DRN 1 and the gate electrode GE 1 is higher.
- a gate insulating film (not shown in the figure) is formed under the gate electrode GE 1 .
- the gate insulating film is thicker than the gate insulating film of the transistors TR 2 and TR 3 .
- an element isolation insulating film formed by an STI method or a LOCOS method is formed between the drain DRN 1 and the gate electrode GE 1 .
- the drain DRN 1 has an n-type well WL 12 and an n-type high concentration region HINPL 13 formed over the surface layer of the n-type well WL 12 .
- the high concentration region HINPL 13 is coupled to a contact CON 3 .
- an n ⁇ -type offset region NOF 11 is formed around the n-type well WL 12 .
- the n-type well WL 12 is formed in the surface layer of the offset region NOF 11 .
- the source SOU 1 has an n-type high concentration region HINPL 12 .
- the high concentration region HINPL 12 is formed in the surface layer of a p-type well WL 21 . Although it is not shown in the figure, a p-type high concentration region is formed at a part of the p-type well WL 21 located adjacent to the high concentration region HINPL 12 . Then a contact CON 2 is coupled to the p-type high concentration region and the high concentration region HINPL 12 .
- an insulating film HMSK 1 and an interlayer insulating film INSL 1 are formed over the substrate SUB.
- the insulating film HMSK 1 is a silicon nitride film for example and the interlayer insulating film INSL 1 is a silicon oxide film for example.
- Contacts CON 2 , CON 3 , CON 4 , CON 5 , CON 6 , and CON 7 are embedded into the insulating film HMSK 1 and the interlayer insulating film INSL 1 .
- the contact CON 2 is coupled to the source SOU 1 of the transistor TR 1 and the contact CON 3 is coupled to the drain DRN 1 of the transistor TR 1 .
- the contact CON 4 is coupled to the source SOU 2 of the transistor TR 2 and the contact CON 5 is coupled to the drain DRN 2 of the transistor TR 2 .
- the contact CON 6 is coupled to the source SOU 3 of the transistor TR 3 and the contact CON 7 is coupled to the drain DRN 3 of the transistor TR 3 .
- a contact coupled to the gate electrode GE 1 a contact coupled to the gate electrode GE 2 , a contact coupled to the gate electrode GE 3 , and a contact coupled to a deep well DWL (described later) are also embedded into the insulating film HMSK 1 and the interlayer insulating film INSL 1 .
- Wires INC 2 , INC 3 , INC 4 , INC 5 , INC 6 , and INC 7 are formed over the interlayer insulating film INSL 1 .
- the wires INC 2 , INC 3 , INC 4 , INC 5 , INC 6 , and INC 7 comprise a metal such as aluminum for example and are coupled to the contacts CON 2 , CON 3 , CON 4 , CON 5 , CON 6 , and CON 7 respectively.
- wires (not shown in the figure) coupled to the respective gate electrodes and a wire (not shown in the figure) coupled to the deep well DWL are also formed over the interlayer insulating film INSL 1 .
- the transistor TR 1 is formed in a first element region EL 1 and the transistors TR 2 and TR 3 are formed in a second element region EL 2 . More specifically, the single transistor TR 1 is formed in the first element region EL 1 . In contrast, the plural transistors TR 2 and TR 3 are formed in the second element region EL 2 . Meanwhile, in FIG. 1 , only a pair of the transistors TR 2 and TR 3 are shown in the second element region EL 2 for the simplification of the figure. Then the first element region EL 1 and the second element region EL 2 are surrounded by element isolation trenches SDTR respectively. The element isolation trenches SDTR pass through the first embedded layer BINPL 1 but do not reach the base substrate BSUB.
- the bottom parts of the element isolation trenches SDTR do not reach even the second embedded layer BINPL 2 .
- the element isolation trenches SDTR are formed so as to be shallower than the second embedded layer BINPL 2 .
- an embedded insulating film BINSL is embedded into the element isolation trenches SDTR.
- the embedded insulating film BINSL is a part of the interlayer insulating film INSL 1 over the substrate SUB.
- the n-type deep well DWL and an embedded contact BCON are further formed in the substrate SUB.
- the bottom face of the deep well DWL reaches the first embedded layer BINPL 1 and the deep well DWL gives a fixed potential to the first embedded layer BINPL 1 .
- the embedded contact BCON is a contact embedded into the substrate SUB and passes through the first embedded layer BINPL 1 and the second embedded layer BINPL 2 . As a result, a fixed potential is given by the embedded contact BCON to the epitaxial layer EPI and the base substrate BSUB under the second embedded layer BINPL 2 .
- a p-type impurity region INPL 1 is formed in the region of the epitaxial layer EP 1 touching the bottom face of the embedded contact BCON.
- the impurity concentration of the impurity region INPL 1 is higher than that of the epitaxial layer EP 1 .
- the contact resistance between the embedded contact BCON and the epitaxial layer EP 1 decreases by forming the impurity region INPL 1 .
- a groove (or hole) into which the embedded contact BCON is embedded is formed through the same process as a contact hole into which the contact CON 2 is embedded for example.
- the groove (or hole) may otherwise be formed through an independent process.
- An insulating film (thermally-oxidized film for example) INSL 2 is formed over the inner face of the groove.
- the embedded contact BCON is insulated from the first embedded layer BINPL 1 and the part of the epitaxial layer EPI located above the first embedded layer BINPL 1 .
- the embedded contact BCON is formed through the same process as the contact CON 2 and other contacts.
- the embedded contact BCON passes through the interlayer insulating film INSL 1 and the insulating film HMSK 1 and the top end is coupled to a wire INC 8 over the interlayer insulating film INSL 1 .
- the potential of the first embedded layer BINPL 1 may be either a floating potential or a fixed potential.
- an impurity region for raising the first embedded layer BINPL 1 electrically to the surface layer of the epitaxial layer EPI is formed in the epitaxial layer EPI.
- the lower part of the impurity region is coupled to the first embedded layer BINPL 1 and a contact is coupled to the upper part of the impurity region.
- FIG. 2 is a plan view of a transistor TR 1 .
- a gate electrode GE 1 surrounds an n-type well WL 12 of a drain DRN 1 and a p-type well WL 21 surrounds the gate electrode GE 1 .
- an element isolation trench SDTR is formed along the sides of a polygon (rectangle in the example shown in the figure) and surrounds the p-type well WL 21 .
- the transistor TR 1 is located inside the element isolation trench SDTR.
- FIGS. 3 to 5 are sectional views showing a manufacturing method of a semiconductor device SD. The figures correspond to FIG. 1 .
- a base substrate BSUB is prepared.
- an epitaxial layer EPI is formed over the base substrate BSUB.
- a second embedded layer BINPL 2 and a first embedded layer BINPL 1 are formed by switching gases for introducing impurities in midstream.
- the second embedded layer BINPL 2 is located immediately over the base substrate BSUB (in other words, at the lowermost layer of the epitaxial layer EPI) for example.
- various kinds of wells including a deep well DWL
- an offset region NOF 11 are formed in the epitaxial layer EPI by an ion implantation method for example.
- a groove is formed in the epitaxial layer EPI and an insulating film, a silicon oxide film for example, is embedded into the groove.
- an element isolation insulating film (not shown in the figure) is formed.
- the various wells and the offset region NOF 11 may otherwise be formed after the element isolation insulating film is formed.
- a gate insulating film for transistors TR 1 , TR 2 , and TR 3 is formed.
- a film (polysilicon film for example) as a material for gate electrodes is formed and the film is selectively removed.
- gate electrodes GE 1 , GE 2 , and GE 3 are formed.
- high concentration regions are formed in the epitaxial layer EPI by an ion implantation method for example.
- sidewalls may be formed over the side faces of the gate electrodes GE 1 , GE 2 , and GE 3 in some cases. In such a case, the high concentration regions are formed after the sidewalls are formed.
- heat treatment is applied after the high concentration regions are formed in the epitaxial layer EPI. Impurities diffuse by the heat treatment and as a result the second embedded layer BINPL 2 gets away from the base substrate BSUB.
- an insulating film HMSK 1 is formed over the epitaxial layer EPI.
- a resist pattern (not shown in the figure) is formed over the insulating film HMSK 1 .
- the resist pattern has openings in the region where element isolation trenches SDTR are to be formed.
- the insulating film HMSK 1 is etched with the resist pattern used as a mask. As a result, the openings are formed in the region of the insulating film HMSK 1 where the element isolation trenches SDTR are to be formed.
- the epitaxial layer EPI (also the element isolation insulating film in some locations) is etched with the insulating film HMSK 1 used as a mask. As a result, the element isolation trenches SDTR are formed. When the resist pattern remains thereafter, the resist pattern is removed.
- an interlayer insulating film INSL 1 is formed.
- parts of the interlayer insulating film INSL 1 are embedded into the element isolation trenches SDTR and come to be an embedded insulating film BINSL.
- voids may be formed in the element isolation trenches SDTR in some cases. Since the voids are occluded with the interlayer insulating film INSL 1 (embedded insulating film BINSL) and are not exposed even at the succeeding processes however, the voids do not influence the quality of the semiconductor device SD.
- a resist pattern (not shown in the figure) is formed over the interlayer insulating film INSL 1 and the interlayer insulating film INSL 1 is etched with the resist pattern used as a mask.
- contact holes for forming contacts are formed.
- a contact hole is also formed in the region of the interlayer insulating film INSL 1 where an embedded contact BCON is to be formed.
- the contact hole reaches down to the bottom of a groove formed in the epitaxial layer EPI. Impurities are injected into the contact hole. As a result, an impurity region INPL 1 is formed.
- a metal such as W is embedded into the contact holes. As a result, the contacts and the embedded contact BCON are formed.
- a metal film (Al for example) is formed over the interlayer insulating film INSL 1 . Successively, the metal film is selectively removed. As a result, wires are formed.
- FIGS. 6A and 6B are views for explaining the distribution of impurities in the depth direction of a substrate SUB.
- FIG. 6A shows the distribution of impurities in a substrate SUB before the substrate SUB is subjected to heat treatment and
- FIG. 6B shows the result of simulating the distribution of the impurities in the substrate SUB after the substrate SUB is subjected to heat treatment.
- a base substrate BSUB contains p-type impurities of a high concentration and an epitaxial layer EPI contains p-type impurities of a concentration lower than that of the base substrate BSUB. Then an n-type second embedded layer BINPL 2 is formed in the region of the epitaxial layer EPI touching the base substrate BSUB.
- the p-type impurities contained in the base substrate BSUB comprise B for example and the n-type impurities contained in the second embedded layer BINPL 2 comprise P for example.
- the second embedded layer BINPL 2 is defined as the region where an n-type impurity concentration is higher than a p-type impurity concentration.
- the second embedded layer BINPL 2 according to the definition is located on the side closer to the surface of the epitaxial layer EPI than the second embedded layer BINPL 2 in the state of FIG. 6A .
- the second embedded layer BINPL 2 when the second embedded layer BINPL 2 is not formed in the state of FIG. 6A , the p-type impurities in the base substrate BSUB diffuse into the epitaxial layer EPI and hence the withstand voltage between the base substrate BSUB and a first embedded layer BINPL 1 deteriorates.
- the second embedded layer BINPL 2 since the second embedded layer BINPL 2 is formed, the p-type impurities diffusing from the base substrate BSUB to the epitaxial layer EPI are offset by the n-type impurities contained in the second embedded layer BINPL 2 .
- the withstand voltage between the base substrate BSUB and a first embedded layer BINPL 1 is inhibited from deteriorating.
- the epitaxial layer EPI is a silicon layer for example
- the thermal diffusion rate of P is nearly identical to the thermal diffusion rate of B at about 1,000° C. Consequently, the offset effect is particularly large when B is elected as the p-type impurities contained in the base substrate BSUB and P is selected as the n-type impurities contained in the second embedded layer BINPL 2 .
- the second embedded layer BINPL 2 is formed so as to be deeper than the element isolation trenches SDTR. As a result, it is possible to bring the second embedded layer BINPL 2 closer to the base substrate BSUB. As a result, it is possible to effectively offset the impurities diffusing from the base substrate BSUB to the epitaxial layer EPI.
- FIGS. 7A and 7B are sectional views showing a manufacturing method of a semiconductor device SD according to Second Embodiment. Firstly, as shown in FIG. 7A , a base substrate BSUB is prepared. Successively, n-type impurities are injected into the base substrate BSUB by thermal diffusion or ion implantation. As a result, a second embedded layer BINPL 2 is formed in the surface layer of the base substrate BSUB.
- an epitaxial layer EPI is formed over the base substrate BSUB.
- the method for forming the epitaxial layer EPI is the same as the method for forming an epitaxial layer EPI in First Embodiment except that the second embedded layer BINPL 2 is not formed.
- FIGS. 8A and 8B are views for explaining the distribution of impurities in the depth direction of a substrate SUB according to the present embodiment and correspond to FIGS. 6A and 6B in First Embodiment.
- FIG. 8A shows the distribution of impurities in a substrate SUB before the substrate SUB is subjected to heat treatment and
- FIG. 8B shows the result of simulating the distribution of the impurities in the substrate SUB after the substrate SUB is subjected to heat treatment.
- a second embedded layer BINPL 2 is formed in the surface layer of a base substrate BSUB.
- the second embedded layer BINPL 2 is defined as the region where the concentration of n-type impurities is higher than the concentration of p-type impurities in the same manner as First Embodiment.
- the second embedded layer BINPL 2 according to the definition is located inside an epitaxial layer EPI in the example shown in the figure.
- the second embedded layer BINPL 2 is formed in the substrate SUB and hence it is possible to inhibit the withstand voltage between the base substrate BSUB and a first embedded layer BINPL 1 from deteriorating.
- FIG. 9 is a sectional view showing the configuration of a semiconductor device SD according to Third Embodiment.
- the semiconductor device SD according to the present embodiment has a configuration similar to the semiconductor device SD according to Second Embodiment except that the semiconductor device SD according to the present embodiment has a third embedded layer BINPL 3 instead of a second embedded layer BINPL 2 .
- the third embedded layer BINPL 3 is a layer into which an element (hereunder described as a diffusion inhibiting element) to inhibit impurities in a base substrate BSUB from thermally diffusing is introduced.
- the third embedded layer BINPL 3 is formed by introducing a diffusion inhibiting element into the surface layer of the base substrate BSUB instead of n-type impurities in FIG. 7A of Second Embodiment.
- the diffusion inhibiting element is at least one of N, C, and 0 for example.
- the concentration of the diffusion inhibiting element in the third embedded layer BINPL 3 is identical to or lower than the concentration of the p-type impurities in the base substrate BSUB and higher than the concentration of the p-type impurities in an epitaxial layer EPI, for example.
- FIGS. 10A and 10B are views for explaining the distribution of impurities in the depth direction of a substrate SUB according to the present embodiment and correspond to FIGS. 8A and 8B in Second Embodiment.
- FIG. 10A shows the distribution of impurities in a substrate SUB before the substrate SUB is subjected to heat treatment and
- FIG. 10B shows the distribution of the impurities in the substrate SUB after the substrate SUB is subjected to heat treatment.
- a third embedded layer BINPL 3 is formed in the surface layer of a base substrate BSUB.
- impurities in the base substrate BSUB diffuse toward an epitaxial layer EPI but the quantity of the diffusion is small because the third embedded layer BINPL 3 is formed.
- a diffusion inhibiting element in the third embedded layer BINPL 3 also diffuses in the substrate SUB. As a result, the width of the third embedded layer BINPL 3 increases.
- the third embedded layer BINPL 3 is formed in the substrate SUB and hence the impurities in the base substrate BSUB hardly diffuse toward the epitaxial layer EPI. As a result, it is possible to inhibit the withstand voltage between the base substrate BSUB and a first embedded layer BINPL 1 from deteriorating.
- FIG. 11 is a sectional view showing the configuration of a semiconductor device SD according to Fourth Embodiment.
- the semiconductor device SD according to the present embodiment has a configuration similar to any one of First to Third Embodiments except that the semiconductor device SD according to the present embodiment has a backside electrode EL instead of an embedded contact BCON.
- the figure shows the case of a configuration similar to First Embodiment.
- the backside electrode EL is formed over the surface of a base substrate BSUB where an epitaxial layer EPI is not formed and gives a fixed potential to the base substrate BSUB.
- the backside electrode EL comprises a metal such as Al for example.
- the backside electrode EL is formed by a sputtering method for example.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Microelectronics & Electronic Packaging (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Insulated Gate Type Field-Effect Transistor (AREA)
- Metal-Oxide And Bipolar Metal-Oxide Semiconductor Integrated Circuits (AREA)
- Element Separation (AREA)
- Electrodes Of Semiconductors (AREA)
Abstract
In the present invention, a first electrically conductive type epitaxial layer is formed over a first electrically conductive type base substrate. The impurity concentration of the epitaxial layer is lower than that of the base substrate. A second electrically conductive type first embedded layer and a second electrically conductive type second embedded layer are formed in the epitaxial layer. The second embedded layer is deeper than the first embedded layer, is kept away from the first embedded layer, and has an impurity concentration lower than the first embedded layer. A transistor is further formed in the epitaxial layer.
Description
- The disclosure of Japanese Patent Application No. 2014-107950 filed on May 26, 2014 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
- The present invention relates to a semiconductor device and is, for example, a technology applicable to a semiconductor device having a diffusion layer embedded into a substrate.
- In a semiconductor device, it sometimes happens that a diffusion layer is embedded into a substrate and a transistor is formed over the diffusion layer. In the transistor, a substance formed by epitaxially growing a semiconductor layer over a semiconductor substrate acting as a base is used as the substrate for example. Then the diffusion layer is: formed by an ion implantation method after the semiconductor layer is formed in some cases; or formed when the semiconductor layer is epitaxially grown in other cases.
- Meanwhile, Japanese Unexamined Patent Application Publication No. Sho 62 (1987)-40719 describes that p-type impurities are diffused over the surface of a p-type substrate acting as a base by a thermal diffusion method and successively an epitaxial layer is grown over the substrate.
- Further, Japanese Unexamined Patent Application Publication No. 2002-176177 describes that a semiconductor substrate is formed by forming an n-type epitaxial layer over the surface of a p-type substrate acting as a base and a trench gate type IGBT is formed by using the semiconductor substrate. In Japanese Unexamined Patent Application Publication No. 2002-176177, the epitaxial layer has a configuration formed by stacking a low-concentration n-type layer over a high-concentration n-type layer.
- When a semiconductor layer is formed over a substrate acting as a base, a diffusion layer is embedded into the semiconductor layer, and a transistor is formed over the diffusion layer, the withstand voltage of the transistor is dominated by the distance between the substrate acting as the base and the diffusion layer in some cases. Since impurities are also introduced into the substrate however, there has been the possibility that the impurities diffuse from the substrate to the semiconductor layer in the manufacturing process of a semiconductor device and the withstand voltage of the transistor deteriorates. Other problems and novel features will be obvious from the descriptions and attached drawings in the present specification.
- According to an embodiment, a first electrically conductive type semiconductor layer is formed over a first electrically conductive type base substrate. The impurity concentration of the semiconductor layer is lower than that of the base substrate. A second electrically conductive type first embedded layer and a second electrically conductive type second embedded layer are formed in the semiconductor layer. The second embedded layer is deeper than the first embedded layer, is kept away from the first embedded layer, and has an impurity concentration lower than the first embedded layer. A transistor is further formed in the semiconductor layer.
- According to the embodiment, it is possible to inhibit: impurities from diffusing from the substrate to the semiconductor layer; and the withstand voltage of the transistor from deteriorating.
-
FIG. 1 is a sectional view showing the configuration of a semiconductor device according to First Embodiment. -
FIG. 2 is a plan view of a transistor. -
FIG. 3 is a sectional view showing a manufacturing method of a semiconductor device. -
FIG. 4 is a sectional view showing the manufacturing method of the semiconductor device. -
FIG. 5 is a sectional view showing the manufacturing method of the semiconductor device. -
FIGS. 6A and 6B are views for explaining the distribution of impurities in the depth direction of a substrate. -
FIGS. 7A and 7B are sectional views showing a manufacturing method of a semiconductor device according to Second Embodiment. -
FIGS. 8A and 8B are views for explaining the distribution of impurities in the depth direction of a substrate. -
FIG. 9 is a sectional view showing the configuration of a semiconductor device according to Third Embodiment. -
FIGS. 10A and 10B are views for explaining the distribution of impurities in the depth direction of a substrate. -
FIG. 11 is a sectional view showing the configuration of a semiconductor device according to Fourth Embodiment. - Embodiments are explained in reference to the drawings hereunder. In all the drawings, similar constituent components are represented by similar reference numerals and explanations are omitted appropriately.
-
FIG. 1 is a sectional view showing the configuration of a semiconductor device SD according to First Embodiment. The semiconductor device SD according to the present embodiment is formed by using a substrate SUB. The substrate SUB is formed by growing an epitaxial layer EPI (semiconductor layer) comprising a semiconductor (for example silicon) over a base substrate BSUB comprising a bulk semiconductor (for example monocrystal silicon). Both the base substrate BSUB and the epitaxial layer EPI are an identical electrically conductive type (first electrically conductive type: for example P-type). The impurity concentration of the base substrate BSUB is higher than that of the epitaxial layer EPI. - A first embedded layer BINPL1 that is an electrically conductive type (second electrically conductive type: for example n-type) different from the epitaxial layer EPI is formed in the epitaxial layer EPI. The first embedded layer BINPL1 is kept away from the base substrate BSUB. The first embedded layer BINPL1: either may be formed when the epitaxial layer EPI is grown epitaxially; or may be formed by an ion implantation method after the epitaxial layer EPI is formed. In the former case, the first embedded layer BINPL1 is formed over the whole surface of the substrate SUB.
- Further, a second embedded layer BINPL2 is formed in the epitaxial layer EPI. The second embedded layer BINPL2 is a second electrically conductive type impurity layer, is deeper than the first embedded layer BINPL1, and is kept away from the first embedded layer BINPL1. The impurity concentration of the second embedded layer BINPL2 is lower than that of the first embedded layer BINPL1. The second embedded layer BINPL2 is formed in order to inhibit: the impurities of the base substrate BSUB from diffusing in the epitaxial layer EPI; and the first electrically conductive type impurity concentration in the lower layer of the epitaxial layer EPI from increasing.
- Then transistors TR2 and TR3 constituting a logic circuit and a transistor TR1 for electric power control are formed in the epitaxial layer EPI. At least the transistor TR1 overlaps with the first embedded layer BINPL1 in a planar view.
- The following explanations are based on the case where the first electrically conductive type is a p-type and the second electrically conductive type is an n-type. It is also possible however that the first electrically conductive type is an n-type and the second electrically conductive type is a p-type.
- The transistor TR2 is an n-type low withstand voltage transistor and has a gate electrode GE2, a source SOU2, and a drain DRN2. The transistor TR3 is a p-type low withstand voltage transistor and has a gate electrode GE3, a source SOU3, and a drain DRN3. The transistors TR2 and TR3 include a CMOS transistor. Meanwhile, a gate insulating film (not shown in the figure) is formed under the gate electrodes GE2 and GE3.
- The transistor TR1 is a horizontal transistor for electric power control and has a withstand voltage higher than the transistors TR2 and TR3. The transistor TR1 has a gate electrode GE1, a source SOU1, and a drain DRN1. The distance between the drain DRN1 and the gate electrode GE1 is larger than the distance between the source SOU1 and the gate electrode GE1. As a result, the withstand voltage between the drain DRN1 and the gate electrode GE1 is higher. A gate insulating film (not shown in the figure) is formed under the gate electrode GE1. The gate insulating film is thicker than the gate insulating film of the transistors TR2 and TR3. Here, an element isolation insulating film formed by an STI method or a LOCOS method is formed between the drain DRN1 and the gate electrode GE1.
- The drain DRN1 has an n-type well WL12 and an n-type high concentration region HINPL13 formed over the surface layer of the n-type well WL12. The high concentration region HINPL13 is coupled to a contact CON3. Further, an n−-type offset region NOF11 is formed around the n-type well WL12. In other words, the n-type well WL12 is formed in the surface layer of the offset region NOF11.
- Meanwhile, the source SOU1 has an n-type high concentration region HINPL12. The high concentration region HINPL12 is formed in the surface layer of a p-type well WL21. Although it is not shown in the figure, a p-type high concentration region is formed at a part of the p-type well WL21 located adjacent to the high concentration region HINPL12. Then a contact CON2 is coupled to the p-type high concentration region and the high concentration region HINPL12.
- Then an insulating film HMSK1 and an interlayer insulating film INSL1 are formed over the substrate SUB. The insulating film HMSK1 is a silicon nitride film for example and the interlayer insulating film INSL1 is a silicon oxide film for example. Contacts CON2, CON3, CON4, CON5, CON6, and CON7 are embedded into the insulating film HMSK1 and the interlayer insulating film INSL1. The contact CON2 is coupled to the source SOU1 of the transistor TR1 and the contact CON3 is coupled to the drain DRN1 of the transistor TR1. The contact CON4 is coupled to the source SOU2 of the transistor TR2 and the contact CON5 is coupled to the drain DRN2 of the transistor TR2. The contact CON6 is coupled to the source SOU3 of the transistor TR3 and the contact CON7 is coupled to the drain DRN3 of the transistor TR3. Meanwhile, although they are not shown in the figure, a contact coupled to the gate electrode GE1, a contact coupled to the gate electrode GE2, a contact coupled to the gate electrode GE3, and a contact coupled to a deep well DWL (described later) are also embedded into the insulating film HMSK1 and the interlayer insulating film INSL1.
- Wires INC2, INC3, INC4, INC5, INC6, and INC7 are formed over the interlayer insulating film INSL1. The wires INC2, INC3, INC4, INC5, INC6, and INC7 comprise a metal such as aluminum for example and are coupled to the contacts CON2, CON3, CON4, CON5, CON6, and CON7 respectively. Meanwhile, wires (not shown in the figure) coupled to the respective gate electrodes and a wire (not shown in the figure) coupled to the deep well DWL are also formed over the interlayer insulating film INSL1.
- The transistor TR1 is formed in a first element region EL1 and the transistors TR2 and TR3 are formed in a second element region EL2. More specifically, the single transistor TR1 is formed in the first element region EL1. In contrast, the plural transistors TR2 and TR3 are formed in the second element region EL2. Meanwhile, in
FIG. 1 , only a pair of the transistors TR2 and TR3 are shown in the second element region EL2 for the simplification of the figure. Then the first element region EL1 and the second element region EL2 are surrounded by element isolation trenches SDTR respectively. The element isolation trenches SDTR pass through the first embedded layer BINPL1 but do not reach the base substrate BSUB. Further in the example shown in the figure, the bottom parts of the element isolation trenches SDTR do not reach even the second embedded layer BINPL2. In other words, the element isolation trenches SDTR are formed so as to be shallower than the second embedded layer BINPL2. - Then an embedded insulating film BINSL is embedded into the element isolation trenches SDTR. In the example shown in the figure, the embedded insulating film BINSL is a part of the interlayer insulating film INSL1 over the substrate SUB.
- Meanwhile, the n-type deep well DWL and an embedded contact BCON are further formed in the substrate SUB. The bottom face of the deep well DWL reaches the first embedded layer BINPL1 and the deep well DWL gives a fixed potential to the first embedded layer BINPL1. The embedded contact BCON is a contact embedded into the substrate SUB and passes through the first embedded layer BINPL1 and the second embedded layer BINPL2. As a result, a fixed potential is given by the embedded contact BCON to the epitaxial layer EPI and the base substrate BSUB under the second embedded layer BINPL2.
- In the example shown in the figure, a p-type impurity region INPL1 is formed in the region of the epitaxial layer EP1 touching the bottom face of the embedded contact BCON. The impurity concentration of the impurity region INPL1 is higher than that of the epitaxial layer EP1. The contact resistance between the embedded contact BCON and the epitaxial layer EP1 decreases by forming the impurity region INPL1.
- A groove (or hole) into which the embedded contact BCON is embedded is formed through the same process as a contact hole into which the contact CON2 is embedded for example. The groove (or hole) may otherwise be formed through an independent process. An insulating film (thermally-oxidized film for example) INSL2 is formed over the inner face of the groove. As a result, the embedded contact BCON is insulated from the first embedded layer BINPL1 and the part of the epitaxial layer EPI located above the first embedded layer BINPL1. Further, the embedded contact BCON is formed through the same process as the contact CON2 and other contacts. As a result, the embedded contact BCON passes through the interlayer insulating film INSL1 and the insulating film HMSK1 and the top end is coupled to a wire INC8 over the interlayer insulating film INSL1.
- Meanwhile, the potential of the first embedded layer BINPL1 may be either a floating potential or a fixed potential. In the latter case, an impurity region for raising the first embedded layer BINPL1 electrically to the surface layer of the epitaxial layer EPI is formed in the epitaxial layer EPI. The lower part of the impurity region is coupled to the first embedded layer BINPL1 and a contact is coupled to the upper part of the impurity region.
-
FIG. 2 is a plan view of a transistor TR1. A gate electrode GE1 surrounds an n-type well WL12 of a drain DRN1 and a p-type well WL21 surrounds the gate electrode GE1. Then an element isolation trench SDTR is formed along the sides of a polygon (rectangle in the example shown in the figure) and surrounds the p-type well WL21. In other words, the transistor TR1 is located inside the element isolation trench SDTR. -
FIGS. 3 to 5 are sectional views showing a manufacturing method of a semiconductor device SD. The figures correspond toFIG. 1 . - Firstly, as shown in
FIG. 3 , a base substrate BSUB is prepared. Successively, an epitaxial layer EPI is formed over the base substrate BSUB. On this occasion, a second embedded layer BINPL2 and a first embedded layer BINPL1 are formed by switching gases for introducing impurities in midstream. At the step, the second embedded layer BINPL2 is located immediately over the base substrate BSUB (in other words, at the lowermost layer of the epitaxial layer EPI) for example. - Successively, as shown in
FIG. 4 , various kinds of wells (including a deep well DWL) and an offset region NOF11 are formed in the epitaxial layer EPI by an ion implantation method for example. Successively, a groove is formed in the epitaxial layer EPI and an insulating film, a silicon oxide film for example, is embedded into the groove. As a result, an element isolation insulating film (not shown in the figure) is formed. Meanwhile, the various wells and the offset region NOF11 may otherwise be formed after the element isolation insulating film is formed. - Successively, a gate insulating film for transistors TR1, TR2, and TR3 is formed. Successively, a film (polysilicon film for example) as a material for gate electrodes is formed and the film is selectively removed. As a result, gate electrodes GE1, GE2, and GE3 are formed. Successively, high concentration regions (HINPL12 and HINPL13 for example) are formed in the epitaxial layer EPI by an ion implantation method for example.
- Meanwhile, sidewalls may be formed over the side faces of the gate electrodes GE1, GE2, and GE3 in some cases. In such a case, the high concentration regions are formed after the sidewalls are formed.
- Further, heat treatment is applied after the high concentration regions are formed in the epitaxial layer EPI. Impurities diffuse by the heat treatment and as a result the second embedded layer BINPL2 gets away from the base substrate BSUB.
- Successively, as shown in
FIG. 5 , an insulating film HMSK1 is formed over the epitaxial layer EPI. Successively, a resist pattern (not shown in the figure) is formed over the insulating film HMSK1. The resist pattern has openings in the region where element isolation trenches SDTR are to be formed. Successively, the insulating film HMSK1 is etched with the resist pattern used as a mask. As a result, the openings are formed in the region of the insulating film HMSK1 where the element isolation trenches SDTR are to be formed. - Successively, the epitaxial layer EPI (also the element isolation insulating film in some locations) is etched with the insulating film HMSK1 used as a mask. As a result, the element isolation trenches SDTR are formed. When the resist pattern remains thereafter, the resist pattern is removed.
- Successively, an interlayer insulating film INSL1 is formed. On this occasion, parts of the interlayer insulating film INSL1 are embedded into the element isolation trenches SDTR and come to be an embedded insulating film BINSL. On this occasion, voids may be formed in the element isolation trenches SDTR in some cases. Since the voids are occluded with the interlayer insulating film INSL1 (embedded insulating film BINSL) and are not exposed even at the succeeding processes however, the voids do not influence the quality of the semiconductor device SD.
- Successively, a resist pattern (not shown in the figure) is formed over the interlayer insulating film INSL1 and the interlayer insulating film INSL1 is etched with the resist pattern used as a mask. As a result, contact holes for forming contacts are formed. In the process, a contact hole is also formed in the region of the interlayer insulating film INSL1 where an embedded contact BCON is to be formed. The contact hole reaches down to the bottom of a groove formed in the epitaxial layer EPI. Impurities are injected into the contact hole. As a result, an impurity region INPL1 is formed. Then a metal such as W is embedded into the contact holes. As a result, the contacts and the embedded contact BCON are formed.
- Successively, a metal film (Al for example) is formed over the interlayer insulating film INSL1. Successively, the metal film is selectively removed. As a result, wires are formed.
-
FIGS. 6A and 6B are views for explaining the distribution of impurities in the depth direction of a substrate SUB.FIG. 6A shows the distribution of impurities in a substrate SUB before the substrate SUB is subjected to heat treatment andFIG. 6B shows the result of simulating the distribution of the impurities in the substrate SUB after the substrate SUB is subjected to heat treatment. - As shown in
FIG. 6A , a base substrate BSUB contains p-type impurities of a high concentration and an epitaxial layer EPI contains p-type impurities of a concentration lower than that of the base substrate BSUB. Then an n-type second embedded layer BINPL2 is formed in the region of the epitaxial layer EPI touching the base substrate BSUB. Here, the p-type impurities contained in the base substrate BSUB comprise B for example and the n-type impurities contained in the second embedded layer BINPL2 comprise P for example. - When the substrate SUB shown in
FIG. 6A is subjected to heat treatment, the impurities contained in the respective layers diffuse thermally. In the state after heat treatment, the second embedded layer BINPL2 is defined as the region where an n-type impurity concentration is higher than a p-type impurity concentration. The second embedded layer BINPL2 according to the definition is located on the side closer to the surface of the epitaxial layer EPI than the second embedded layer BINPL2 in the state ofFIG. 6A . - Meanwhile, when the second embedded layer BINPL2 is not formed in the state of
FIG. 6A , the p-type impurities in the base substrate BSUB diffuse into the epitaxial layer EPI and hence the withstand voltage between the base substrate BSUB and a first embedded layer BINPL1 deteriorates. - In the present embodiment in contrast, since the second embedded layer BINPL2 is formed, the p-type impurities diffusing from the base substrate BSUB to the epitaxial layer EPI are offset by the n-type impurities contained in the second embedded layer BINPL2. As a result, the withstand voltage between the base substrate BSUB and a first embedded layer BINPL1 is inhibited from deteriorating. Here, when the epitaxial layer EPI is a silicon layer for example, the thermal diffusion rate of P is nearly identical to the thermal diffusion rate of B at about 1,000° C. Consequently, the offset effect is particularly large when B is elected as the p-type impurities contained in the base substrate BSUB and P is selected as the n-type impurities contained in the second embedded layer BINPL2.
- Further, the second embedded layer BINPL2 is formed so as to be deeper than the element isolation trenches SDTR. As a result, it is possible to bring the second embedded layer BINPL2 closer to the base substrate BSUB. As a result, it is possible to effectively offset the impurities diffusing from the base substrate BSUB to the epitaxial layer EPI.
-
FIGS. 7A and 7B are sectional views showing a manufacturing method of a semiconductor device SD according to Second Embodiment. Firstly, as shown inFIG. 7A , a base substrate BSUB is prepared. Successively, n-type impurities are injected into the base substrate BSUB by thermal diffusion or ion implantation. As a result, a second embedded layer BINPL2 is formed in the surface layer of the base substrate BSUB. - Successively, an epitaxial layer EPI is formed over the base substrate BSUB. The method for forming the epitaxial layer EPI is the same as the method for forming an epitaxial layer EPI in First Embodiment except that the second embedded layer BINPL2 is not formed.
- The succeeding processes are the same as First Embodiment.
-
FIGS. 8A and 8B are views for explaining the distribution of impurities in the depth direction of a substrate SUB according to the present embodiment and correspond toFIGS. 6A and 6B in First Embodiment.FIG. 8A shows the distribution of impurities in a substrate SUB before the substrate SUB is subjected to heat treatment andFIG. 8B shows the result of simulating the distribution of the impurities in the substrate SUB after the substrate SUB is subjected to heat treatment. - As shown in
FIG. 8A , in the state before heat treatment, a second embedded layer BINPL2 is formed in the surface layer of a base substrate BSUB. As shown inFIG. 8B in contrast, when a substrate SUB is subjected to heat treatment, the second embedded layer BINPL2 is defined as the region where the concentration of n-type impurities is higher than the concentration of p-type impurities in the same manner as First Embodiment. The second embedded layer BINPL2 according to the definition is located inside an epitaxial layer EPI in the example shown in the figure. - In the present embodiment too, the second embedded layer BINPL2 is formed in the substrate SUB and hence it is possible to inhibit the withstand voltage between the base substrate BSUB and a first embedded layer BINPL1 from deteriorating.
-
FIG. 9 is a sectional view showing the configuration of a semiconductor device SD according to Third Embodiment. The semiconductor device SD according to the present embodiment has a configuration similar to the semiconductor device SD according to Second Embodiment except that the semiconductor device SD according to the present embodiment has a third embedded layer BINPL3 instead of a second embedded layer BINPL2. - The third embedded layer BINPL3 is a layer into which an element (hereunder described as a diffusion inhibiting element) to inhibit impurities in a base substrate BSUB from thermally diffusing is introduced. The third embedded layer BINPL3 is formed by introducing a diffusion inhibiting element into the surface layer of the base substrate BSUB instead of n-type impurities in
FIG. 7A of Second Embodiment. The diffusion inhibiting element is at least one of N, C, and 0 for example. The concentration of the diffusion inhibiting element in the third embedded layer BINPL3 is identical to or lower than the concentration of the p-type impurities in the base substrate BSUB and higher than the concentration of the p-type impurities in an epitaxial layer EPI, for example. -
FIGS. 10A and 10B are views for explaining the distribution of impurities in the depth direction of a substrate SUB according to the present embodiment and correspond toFIGS. 8A and 8B in Second Embodiment.FIG. 10A shows the distribution of impurities in a substrate SUB before the substrate SUB is subjected to heat treatment andFIG. 10B shows the distribution of the impurities in the substrate SUB after the substrate SUB is subjected to heat treatment. - As shown in
FIG. 10A , in the state before heat treatment, a third embedded layer BINPL3 is formed in the surface layer of a base substrate BSUB. As shown inFIG. 10B in contrast, when the substrate SUB is subjected to heat treatment, impurities in the base substrate BSUB diffuse toward an epitaxial layer EPI but the quantity of the diffusion is small because the third embedded layer BINPL3 is formed. Here, a diffusion inhibiting element in the third embedded layer BINPL3 also diffuses in the substrate SUB. As a result, the width of the third embedded layer BINPL3 increases. - In the present embodiment, the third embedded layer BINPL3 is formed in the substrate SUB and hence the impurities in the base substrate BSUB hardly diffuse toward the epitaxial layer EPI. As a result, it is possible to inhibit the withstand voltage between the base substrate BSUB and a first embedded layer BINPL1 from deteriorating.
-
FIG. 11 is a sectional view showing the configuration of a semiconductor device SD according to Fourth Embodiment. The semiconductor device SD according to the present embodiment has a configuration similar to any one of First to Third Embodiments except that the semiconductor device SD according to the present embodiment has a backside electrode EL instead of an embedded contact BCON. The figure shows the case of a configuration similar to First Embodiment. - The backside electrode EL is formed over the surface of a base substrate BSUB where an epitaxial layer EPI is not formed and gives a fixed potential to the base substrate BSUB. The backside electrode EL comprises a metal such as Al for example. The backside electrode EL is formed by a sputtering method for example.
- In the present embodiment too, it is possible to inhibit the withstand voltage between the base substrate BSUB and a first embedded layer BINPL1 from deteriorating.
- Although the invention established by the present inventors has heretofore been explained concretely on the basis of the embodiments, it goes without saying that the present invention is not limited to the embodiments and can be modified variously within the scope not departing from the tenor of the invention.
Claims (5)
1. A semiconductor device having: a first electrically conductive type base substrate; a first electrically conductive type semiconductor layer being formed over the base substrate and having an impurity concentration lower than the base substrate; a second electrically conductive type first embedded layer formed in the semiconductor layer; a second embedded layer being formed in the semiconductor layer, being deeper than the first embedded layer, being kept away from the first embedded layer, and having an impurity concentration lower than the first embedded layer; and transistors formed in the semiconductor layer.
2. A semiconductor device according to claim 1 ,
wherein the semiconductor device has trenches being formed in the semiconductor layer and surrounding the transistors and an insulating film embedded into the trenches; and the bottom faces of the trenches are located at positions shallower than the second embodiment layer.
3. A semiconductor device according to claim 1 ,
wherein the semiconductor device has a hole formed in the semiconductor layer, an insulating layer formed over the side face of the hole, and a conductor embedded into the hole; and the bottom face of the hole is deeper than the second embedded layer.
4. A semiconductor device according to claim 3 ,
wherein the semiconductor device has a first electrically conductive type region being formed in the semiconductor layer, being located at the bottom part of the hole, and having an impurity concentration higher than the semiconductor layer.
5. A semiconductor device according to claim 1 ,
wherein P is introduced into the second embedded layer and B is introduced into the base substrate.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US16/019,047 US20180308964A1 (en) | 2014-05-26 | 2018-06-26 | Semiconductor device |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014107950A JP6300638B2 (en) | 2014-05-26 | 2014-05-26 | Semiconductor device |
JP2014-107950 | 2014-05-26 | ||
US14/712,894 US10062773B2 (en) | 2014-05-26 | 2015-05-14 | Semiconductor device having a transistor and first and second embedded layers |
US16/019,047 US20180308964A1 (en) | 2014-05-26 | 2018-06-26 | Semiconductor device |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/712,894 Continuation US10062773B2 (en) | 2014-05-26 | 2015-05-14 | Semiconductor device having a transistor and first and second embedded layers |
Publications (1)
Publication Number | Publication Date |
---|---|
US20180308964A1 true US20180308964A1 (en) | 2018-10-25 |
Family
ID=53002622
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/712,894 Active 2035-07-16 US10062773B2 (en) | 2014-05-26 | 2015-05-14 | Semiconductor device having a transistor and first and second embedded layers |
US16/019,047 Abandoned US20180308964A1 (en) | 2014-05-26 | 2018-06-26 | Semiconductor device |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/712,894 Active 2035-07-16 US10062773B2 (en) | 2014-05-26 | 2015-05-14 | Semiconductor device having a transistor and first and second embedded layers |
Country Status (6)
Country | Link |
---|---|
US (2) | US10062773B2 (en) |
EP (1) | EP2950339A1 (en) |
JP (1) | JP6300638B2 (en) |
KR (1) | KR20150136015A (en) |
CN (1) | CN105140223A (en) |
TW (1) | TW201606939A (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102017102127B4 (en) | 2017-02-03 | 2023-03-09 | Infineon Technologies Ag | Method of manufacturing semiconductor devices using epitaxy and semiconductor devices with a lateral structure |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20030151088A1 (en) * | 2002-02-08 | 2003-08-14 | Taiwan Semiconductor Manufacturing Co., Ltd. | Lateral double diffused metal oxide semiconductor (LDMOS) device with aligned buried layer isolation layer |
US20050004593A1 (en) * | 2001-10-30 | 2005-01-06 | Depuy Spine, Inc. | Non cannulated dilators |
US20080013593A1 (en) * | 2006-06-21 | 2008-01-17 | Ken-Ichi Kawabata | Phantom |
US20140017545A1 (en) * | 2010-10-04 | 2014-01-16 | Dana Canada Corporation | Conformal fluid-cooled heat exchanger for battery |
Family Cites Families (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5887866A (en) * | 1981-11-20 | 1983-05-25 | Hitachi Ltd | Semiconductor device |
JPS6240719A (en) | 1985-08-16 | 1987-02-21 | Nec Corp | Manufacture of epitaxial wafer |
JPH0364029A (en) * | 1989-08-02 | 1991-03-19 | Hitachi Ltd | Semiconductor device and manufacture thereof |
JPH10125916A (en) * | 1996-10-24 | 1998-05-15 | Matsushita Electric Ind Co Ltd | Semiconductor device and manufacture thereof |
JP4528460B2 (en) * | 2000-06-30 | 2010-08-18 | 株式会社東芝 | Semiconductor element |
JP2002134627A (en) * | 2000-10-23 | 2002-05-10 | Sharp Corp | Semiconductor device and its manufacturing method |
JP2002176177A (en) | 2000-12-07 | 2002-06-21 | Denso Corp | Semiconductor device and its manufacturing method |
JP4728508B2 (en) * | 2001-06-11 | 2011-07-20 | 株式会社東芝 | Method for manufacturing vertical power semiconductor device |
US6664608B1 (en) * | 2001-11-30 | 2003-12-16 | Sun Microsystems, Inc. | Back-biased MOS device |
US6943426B2 (en) * | 2002-08-14 | 2005-09-13 | Advanced Analogic Technologies, Inc. | Complementary analog bipolar transistors with trench-constrained isolation diffusion |
JP4437388B2 (en) * | 2003-02-06 | 2010-03-24 | 株式会社リコー | Semiconductor device |
TWI223442B (en) * | 2003-09-02 | 2004-11-01 | Nanya Technology Corp | DRAM cell array and its manufacturing method |
US8253196B2 (en) * | 2004-01-29 | 2012-08-28 | Enpirion, Inc. | Integrated circuit with a laterally diffused metal oxide semiconductor device and method of forming the same |
US7714381B2 (en) * | 2005-04-01 | 2010-05-11 | Semiconductor Components Industries, Llc | Method of forming an integrated power device and structure |
JP5164333B2 (en) * | 2005-12-28 | 2013-03-21 | オンセミコンダクター・トレーディング・リミテッド | Semiconductor device |
JP2007221024A (en) * | 2006-02-20 | 2007-08-30 | Toshiba Corp | Semiconductor device |
JP4798119B2 (en) * | 2007-11-06 | 2011-10-19 | 株式会社デンソー | Silicon carbide semiconductor device and manufacturing method thereof |
JP4577355B2 (en) * | 2007-12-26 | 2010-11-10 | 株式会社デンソー | Silicon carbide semiconductor device and manufacturing method thereof |
US7977715B2 (en) * | 2008-03-17 | 2011-07-12 | Fairchild Semiconductor Corporation | LDMOS devices with improved architectures |
US20110156682A1 (en) * | 2009-12-30 | 2011-06-30 | Dev Alok Girdhar | Voltage converter with integrated schottky device and systems including same |
JP5120418B2 (en) * | 2010-06-07 | 2013-01-16 | 富士電機株式会社 | Semiconductor device |
CN102376548A (en) * | 2010-08-26 | 2012-03-14 | 上海华虹Nec电子有限公司 | Method for reducing auto-doping and external diffusion in epitaxial process |
JP2012169384A (en) * | 2011-02-11 | 2012-09-06 | Denso Corp | Silicon carbide semiconductor device and method of manufacturing the same |
US9287371B2 (en) * | 2012-10-05 | 2016-03-15 | Semiconductor Components Industries, Llc | Semiconductor device having localized charge balance structure and method |
-
2014
- 2014-05-26 JP JP2014107950A patent/JP6300638B2/en active Active
-
2015
- 2015-04-28 EP EP15165397.9A patent/EP2950339A1/en not_active Withdrawn
- 2015-05-14 US US14/712,894 patent/US10062773B2/en active Active
- 2015-05-21 KR KR1020150071077A patent/KR20150136015A/en unknown
- 2015-05-22 TW TW104116362A patent/TW201606939A/en unknown
- 2015-05-25 CN CN201510272590.8A patent/CN105140223A/en active Pending
-
2018
- 2018-06-26 US US16/019,047 patent/US20180308964A1/en not_active Abandoned
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20050004593A1 (en) * | 2001-10-30 | 2005-01-06 | Depuy Spine, Inc. | Non cannulated dilators |
US20030151088A1 (en) * | 2002-02-08 | 2003-08-14 | Taiwan Semiconductor Manufacturing Co., Ltd. | Lateral double diffused metal oxide semiconductor (LDMOS) device with aligned buried layer isolation layer |
US20080013593A1 (en) * | 2006-06-21 | 2008-01-17 | Ken-Ichi Kawabata | Phantom |
US20140017545A1 (en) * | 2010-10-04 | 2014-01-16 | Dana Canada Corporation | Conformal fluid-cooled heat exchanger for battery |
Also Published As
Publication number | Publication date |
---|---|
KR20150136015A (en) | 2015-12-04 |
TW201606939A (en) | 2016-02-16 |
EP2950339A1 (en) | 2015-12-02 |
US20150340479A1 (en) | 2015-11-26 |
US10062773B2 (en) | 2018-08-28 |
JP6300638B2 (en) | 2018-03-28 |
JP2015225877A (en) | 2015-12-14 |
CN105140223A (en) | 2015-12-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US10211299B2 (en) | Semiconductor device and semiconductor device manufacturing method | |
US8643089B2 (en) | Semiconductor device and fabricating method thereof | |
US8269272B2 (en) | Semiconductor device and method for manufacturing the same | |
JP6365165B2 (en) | Manufacturing method of semiconductor device | |
US10756169B2 (en) | Semiconductor device and method of manufacturing the same | |
WO2015174197A1 (en) | Semiconductor device and method for manufacturing semiconductor device | |
US20160149029A1 (en) | Semiconductor device and method for manufacturing semiconductor device | |
JP2013008716A (en) | Semiconductor device and manufacturing method of the same | |
JP2018085373A (en) | Semiconductor device and method for manufacturing the same | |
JP6238234B2 (en) | Semiconductor device | |
US7705399B2 (en) | Semiconductor device with field insulation film formed therein | |
JP2010010408A (en) | Semiconductor device and method of manufacturing the same | |
US20170012136A1 (en) | Semiconductor device and manufacturing method thereof | |
KR20110078621A (en) | Semiconductor device, and fabricating method thereof | |
JP2015056643A (en) | Semiconductor device manufacturing method | |
JP2009055027A (en) | Method of manufacturing mos transistor, and mos transistor manufactured by the same | |
US20210043737A1 (en) | Nitride semiconducotr deivce manufacturing method and device | |
JP6061504B2 (en) | Semiconductor device and manufacturing method of semiconductor device | |
US20180308964A1 (en) | Semiconductor device | |
KR101950003B1 (en) | Semiconductor device and method for forming the same | |
US20110204423A1 (en) | Semiconductor device and manufacturing method thereof | |
JP2007180244A (en) | Semiconductor device and its manufacturing method | |
TW201417165A (en) | Use of plate oxide layers to increase bulk oxide thickness in semiconductor devices | |
KR20110037031A (en) | Semiconductor device and a method for manufacturing the same | |
TW201304139A (en) | Trenched power semiconductor device and fabrication method thereof |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STPP | Information on status: patent application and granting procedure in general |
Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: FINAL REJECTION MAILED |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |