US20200258773A1 - Production of semiconductor regions in an electronic chip - Google Patents

Production of semiconductor regions in an electronic chip Download PDF

Info

Publication number
US20200258773A1
US20200258773A1 US16/860,392 US202016860392A US2020258773A1 US 20200258773 A1 US20200258773 A1 US 20200258773A1 US 202016860392 A US202016860392 A US 202016860392A US 2020258773 A1 US2020258773 A1 US 2020258773A1
Authority
US
United States
Prior art keywords
region
layer
silicon nitride
filling
over
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
Application number
US16/860,392
Inventor
Franck Julien
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STMicroelectronics Rousset SAS
Original Assignee
STMicroelectronics Rousset SAS
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by STMicroelectronics Rousset SAS filed Critical STMicroelectronics Rousset SAS
Priority to US16/860,392 priority Critical patent/US20200258773A1/en
Publication of US20200258773A1 publication Critical patent/US20200258773A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • 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
    • H01L21/823857—Complementary field-effect transistors, e.g. CMOS with a particular manufacturing method of the gate insulating layers, e.g. different gate insulating layer thicknesses, particular gate insulator materials or particular gate insulator implants
    • 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
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/76—Making of isolation regions between components
    • H01L21/762—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers
    • H01L21/76224—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers using trench refilling with dielectric materials
    • 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
    • H01L21/02041—Cleaning
    • H01L21/02057—Cleaning during device manufacture
    • H01L21/0206—Cleaning during device manufacture during, before or after processing of insulating layers
    • 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
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
    • H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
    • H01L21/02123—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon
    • H01L21/02164—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon the material being a silicon oxide, e.g. SiO2
    • 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
    • H01L21/02104—Forming layers
    • H01L21/02107—Forming insulating materials on a substrate
    • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
    • H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
    • H01L21/02123—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon
    • H01L21/0217—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing silicon the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz
    • 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 at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
    • H01L21/28008—Making conductor-insulator-semiconductor electrodes
    • H01L21/28017—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon
    • H01L21/28026—Making conductor-insulator-semiconductor electrodes the insulator being formed after the semiconductor body, the semiconductor being silicon characterised by the conductor
    • H01L21/28123—Lithography-related aspects, e.g. sub-lithography lengths; Isolation-related aspects, e.g. to solve problems arising at the crossing with the side of the device isolation; Planarisation aspects
    • 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 at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
    • H01L21/3105—After-treatment
    • H01L21/31051—Planarisation of the insulating layers
    • H01L21/31053—Planarisation of the insulating layers involving a dielectric removal step
    • 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 at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
    • H01L21/3105—After-treatment
    • H01L21/311—Etching the insulating layers by chemical or physical means
    • H01L21/31105—Etching inorganic layers
    • H01L21/31111—Etching inorganic layers by chemical means
    • 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
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/76—Making of isolation regions between components
    • H01L21/762—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers
    • H01L21/7624—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers using semiconductor on insulator [SOI] technology
    • H01L21/76264—SOI together with lateral isolation, e.g. using local oxidation of silicon, or dielectric or polycristalline material refilled trench or air gap isolation regions, e.g. completely isolated semiconductor islands
    • H01L21/76283—Lateral isolation by refilling of trenches with dielectric material
    • 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
    • H01L21/823878—Complementary field-effect transistors, e.g. CMOS isolation region manufacturing related aspects, e.g. to avoid interaction of isolation region with adjacent structure
    • 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
    • H01L21/84—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 other than a semiconductor body, e.g. being an insulating body
    • 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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
    • 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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
    • H01L27/0928—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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier 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 comprising both N- and P- wells in the substrate, e.g. twin-tub
    • 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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
    • H01L27/12—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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body
    • H01L27/1203—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 at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body the substrate comprising an insulating body on a semiconductor body, e.g. SOI
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. 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
    • H01L29/0642—Isolation within the component, i.e. internal isolation
    • H01L29/0649—Dielectric regions, e.g. SiO2 regions, air gaps
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. 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
    • H01L29/66568—Lateral single gate silicon transistors
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10B—ELECTRONIC MEMORY DEVICES
    • H10B41/00—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates
    • H10B41/30—Electrically erasable-and-programmable ROM [EEPROM] devices comprising floating gates characterised by the memory core region
    • 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
    • H01L21/823828—Complementary field-effect transistors, e.g. CMOS with a particular manufacturing method of the gate conductors, e.g. particular materials, shapes
    • H01L21/82385—Complementary field-effect transistors, e.g. CMOS with a particular manufacturing method of the gate conductors, e.g. particular materials, shapes gate conductors with different shapes, lengths or dimensions

Definitions

  • the present patent application relates to a method for producing semiconductor regions in an electronic chip.
  • one problem in such transistors is that, in general, the smaller the transistors, the higher, in relative value, the leakage current. This results in high energy consumption.
  • transistors designed to be identical in fact generally exhibit different electrical characteristics, in particular different threshold voltages.
  • the differences between these electrical characteristics usually tend to get worse when the operating temperature decreases. This results in diverse difficulties in actually obtaining the envisaged electrical characteristics. These difficulties arise particularly in the case where the chip is provided for analogue operation, for example in a measurement device, and/or for cold operation, for example at negative ambient temperature. This usually leads to certain chips being rejected during post-fabrication checking.
  • an electronic chip can comprise memory points of floating gate transistor type, surmounted by a control gate.
  • memory points of floating gate transistor type, surmounted by a control gate.
  • such memory points exhibit problems of degradation of the transistor's gate insulator due to the fact that relatively high programming voltages are required to be applied.
  • the present patent application relates to a method for producing semiconductor regions in an electronic chip.
  • Particular embodiments relate to semiconductor regions intended for the formation of N-channel and P-channel transistors and/or memory points, and a device comprising such regions.
  • Embodiments can mitigate all or some of the drawbacks described above.
  • one embodiment provides a method for fabricating first and second semiconductor regions separated by isolating trenches.
  • a semiconductor substrate is covered with a first silicon nitride layer.
  • the first region is covered with a protection layer that can be etched selectively with respect to the silicon nitride.
  • the structure is covered with a second silicon nitride layer.
  • the trenches are etched through the second and first silicon nitride layers and filled with a filling silicon oxide to a level situated above the protection layer.
  • the second silicon nitride layer and the part of the first silicon nitride layer situated on the second region are selectively removed and the protection layer is removed.
  • the filling oxide is selectively etched by wet etching, thus resulting in pits on the surface of the filling oxide around the second region.
  • the part of the first silicon nitride layer situated on the first region is selectively removed.
  • the protection layer is a first silicon oxide layer and the protection layer is removed selectively by the said wet etching.
  • the method further comprises cleaning the structure.
  • the method further comprises the formation of a second silicon oxide layer on the substrate.
  • the second silicon oxide layer can be removed when the structure is cleaned.
  • the trenches are filled with the filling oxide to a level situated above the second silicon nitride layer.
  • the portions of the structure that are situated above the part of the second silicon nitride layer situated on the second region are removed by chemical-mechanical polishing.
  • the oxide filling can be selectively etched.
  • the trenches are filled to a level between 2 and 15 nm above the protection layer.
  • the second silicon nitride layer after filling the trenches, has in the first region a thickness of between 30 and 100 nm.
  • the protection layer has a thickness of between 2 and 20 nm.
  • the method further comprises forming by thermal oxidation a third silicon oxide layer on the second region.
  • the third silicon oxide layer can be removed when the protection layer is removed.
  • the substrate is the upper semiconductor layer of an SOI structure.
  • the substrate is a bulk substrate.
  • One embodiment provides the method hereinabove for the simultaneous fabrication of an N-channel transistor and of a P-channel transistor.
  • the method includes P-type doping the first region and N-type doping the second region. After selectively removing the part of the first silicon nitride layer situated on the first region, the N-channel transistor is formed in and on the first region and the P-channel transistor is formed in and on the second region.
  • One embodiment provides a device comprising first and second semiconductor regions separated by trenches filled with an insulator.
  • the surface of the insulator has, around the second region, a shape in the form of pits and, around the first region, a shape which is different from the shape around the second region.
  • One embodiment provides an electronic chip comprising the device hereinabove, an N-channel transistor situated in and on the first region, and a P-channel transistor situated in and on the second region.
  • FIGS. 1A to 1E are partial and schematic sectional views illustrating steps of a method for fabricating a P-channel transistor
  • FIG. 1F is a schematic view from above of the structure of FIG. 1E ;
  • FIGS. 2A to 2H are partial and schematic sectional views illustrating steps of an embodiment of a method for fabricating an N-channel transistor and a P-channel transistor;
  • FIG. 2I is a schematic view from above of the structure of FIG. 2H .
  • FIGS. 1A to 1E are partial and schematic sectional views illustrating steps of a method for fabricating a P-channel transistor.
  • a semiconductor substrate 10 comprises by way of example an N-type doped well 12 N.
  • an N-type doped region 16 N has been formed, and its doping level has been selected as a function of the desired electrical characteristics of the transistor.
  • the well 12 N and the region 16 N will be doped in later steps of the method.
  • the substrate is covered with a fine silicon oxide layer 14 , of thickness typically between 2 and 20 nm.
  • a silicon nitride layer 20 is thereafter deposited on the structure, and then trenches 22 passing through the silicon nitride are etched (only halves of the trenches are visible in the figures). The trenches penetrate into the substrate and delimit a portion of the region 16 N.
  • the trenches are filled with an insulator, for example silicon oxide, and then a planarization is carried out as far as the upper level of the silicon nitride 20 .
  • an insulator for example silicon oxide
  • the insulator of the trenches 22 is selectively etched with respect to the silicon nitride 20 , for example to a level situated above the region 16 N.
  • the silicon nitride is removed by selective etching with respect to the insulator of the trenches 22 .
  • the structure is thereafter cleaned, so as to eliminate the oxide of the layer 14 , still present on the region 16 N.
  • This cleaning is, for example, carried out in a solution based on hydrofluoric acid. This cleaning causes the formation of an annular pit 28 on the surface of the insulator of the trenches around the region 16 N.
  • a P-channel MOS transistor is formed in and on the region 16 N.
  • a gate insulator layer 30 and a gate 32 are formed.
  • FIG. 1F is a view from above of the structure of FIG. 1E .
  • the insulating layer 30 is not represented.
  • the gate 32 extends over the width of the region 16 N. Drain and source regions 34 have been formed on each side of the gate.
  • the parameters of the method hereinabove in particular the etching of the insulator of the trenches 22 in the step of FIG. 1C and the cleaning in the step of FIG. 1D , have been adjusted so as to optimize the electrical characteristics of the transistor, for example to minimize its leakage current. This adjustment is for example carried out by trials. Indeed, the electrical characteristics, such as the threshold voltage and the leakage current, are different at the edges and at the center of the transistor because of diverse edge effects. Adjusting the parameters of the method makes it possible to obtain a pit shape which reduces these edge effects.
  • a method making it possible to obtain a P-channel transistor of optimal electrical characteristics has been described hereinabove.
  • this method is not suitable for obtaining an N-channel transistor of optimal electrical characteristics.
  • the edge effects are different in the N-channel transistor and in the P-channel transistor.
  • the dopant atoms tend to migrate in the insulator of the trenches in the course of diverse annealings provided for in the method, especially when dealing with boron atoms and trenches filled with silicon oxide. It follows from this that the doping level of the region 16 P is lower at the edges of the transistor than at the center of the transistor.
  • the pit shape obtained in the P-channel transistor is not the shape which makes it possible to minimize the edge effects of the N-channel transistor.
  • FIGS. 2A to 2H are partial and schematic sectional views illustrating steps of an embodiment of a method for fabricating an N-channel transistor on the left side of the figures and of a P-channel transistor on the right side. This method makes it possible to optimize the electrical characteristics of the P-channel transistors and of the N-channel transistors.
  • a substrate 10 has been provided.
  • the substrate 10 is here by way of example a bulk semiconductor substrate, of silicon for example.
  • the left part of the substrate portion represented is a P-type doped well 12 P.
  • the right part of the substrate portion represented is an N-type doped well 12 N.
  • the substrate may be a semiconductor layer covering an insulating layer on a support, that is to say the upper semiconductor layer of an SOI (“Silicon On Insulator”) structure.
  • a P-type doped layer 16 P′, and, on the right side, an N-type doped layer 16 N′ are implanted in the substrate.
  • the doping levels of the layer 16 P′ and of the layer 16 N′ are, for example, greater than 10 17 atoms/cm 3 .
  • the layers 16 P′ and 16 N′ can extend throughout the thickness of the thin monocrystalline silicon layer.
  • the well 12 P, the well 12 N, the layer 16 P′ and/or the layer 16 N′ instead of being doped starting from the step of FIG. 2A , may be doped in later steps of the method.
  • the substrate is covered with a silicon oxide layer 14 of thickness for example of between 2 and 20 nm.
  • a silicon nitride layer 20 covering the structure is formed.
  • the thickness of the layer 20 is, for example, between 30 and 100 nm.
  • the layer 40 preferably has a thickness of between 2 and 20 nm. The function of the layer 40 will subsequently be to protect the silicon nitride layer 20 .
  • the structure is covered with a silicon nitride layer 42 .
  • the thickness of the layer 42 is for example between 30 and 100 nm. It follows from this that the silicon nitride layers 20 and 42 are directly on one another on the side of the region 16 N′, and are separated by the layer 40 on the side of the region 16 P′.
  • trenches 22 are etched, passing all the way through, on the left side, the two silicon nitride layers 20 and 42 and the region 16 P′, and, on the right side, the layers 20 , 40 and 42 and the region 16 N′.
  • the trenches 22 delimit a semiconductor region 16 P in the layer 16 P′ and a semiconductor region 16 N in the layer 16 N′.
  • the trenches 22 surround the regions 16 P and 16 N.
  • the trenches 22 are filled with an insulator, for example silicon oxide.
  • an insulator for example silicon oxide.
  • the whole of the structure is covered with this insulator to a level situated above that of the silicon nitride layer 42 , and a chemical-mechanical polishing is undertaken thereafter.
  • the polishing removes the parts of the structure which are situated above the upper level of the silicon nitride covering the region 16 N, or above a level situated in the silicon nitride layer 42 .
  • the silicon nitride of the layer 42 is flush with the surface of the insulator of the trenches, and the layer 42 has on the side of the region 16 P a thickness of for example between 30 and 100 nm.
  • the insulator of the trenches 22 is etched selectively to a level situated above that of the protection layer 40 , for example by a hydrofluoric acid solution or one based on hydrofluoric acid.
  • the surface of the insulator of the trenches after etching is situated between 2 and 15 nm above the upper surface of the protection layer 40 .
  • a selective etching of the silicon nitride is performed, for example by a phosphoric acid solution or one based on phosphoric acid.
  • the silicon nitride of the two layers 20 and 42 is removed.
  • the silicon nitride of the layer 42 is removed, but the silicon nitride of the layer 20 is not removed, since it is protected by the layer 40 .
  • the insulator of the trenches is thereafter etched and the protection layer 40 is removed, for example, by a hydrofluoric acid solution or one based on hydrofluoric acid.
  • the etching is continued until the level of the insulator of the trenches, dependent on the desired characteristics of the transistors, is for example between 20 nm below and 30 nm above the regions 16 N and 16 P.
  • the possible layer 14 is removed in this step on the side of the region 16 N. This etching forms an annular pit 28 on the surface of the insulator of the trenches around the region 16 N. Due to the presence of the silicon nitride of the layer 20 above the region 16 P, the etching is not accompanied by pit formation around the region 16 P.
  • the silicon nitride of the layer 20 is selectively removed on the region 16 P, for example by a solution based on phosphoric acid.
  • a cleaning is undertaken thereafter, for example by a hydrofluoric acid solution or one based on hydrofluoric acid.
  • the possible layer 14 is thus removed on the side of the region 16 P.
  • This step further hollows out the pits 28 around the regions 16 N.
  • the surface of the insulator of the trenches 22 has a different shape from that of the pits 28 . By way of example, starting from the edge of the region 16 P, the surface meets up with the upper level of the insulator of the trenches via slopes 50 .
  • the N-channel and P-channel transistors in and on respectively the regions 16 P and 16 N are produced.
  • a gate insulator layer 0 and the gates 32 are formed.
  • the gate insulator 30 is formed by thermal oxidation and/or by deposition.
  • the gate insulator can comprise a material with high dielectric permittivity such as, for example, hafnium oxide.
  • the gate insulator is deposited in a compliant manner, and thus, on the side of the region 16 P, in a part 52 situated on the slopes 50 (approximately plumb with the edges of the region 16 P), the thickness, taken vertically, of the gate insulator is greater than that of the gate insulator in the horizontal parts (that is to say central parts situated above a central part of the region 16 P).
  • FIG. 2I is a schematic view from above of the structure of FIG. 2H , in which the gate insulator is not represented.
  • the gates 32 extend across the regions 16 P and 16 N between drain and source regions 34 .
  • the gate may be common to two transistors.
  • a single transistor has been represented in and on each of the regions 16 P and 16 N, but it is possible to form several transistors on each of the regions 16 P and 16 N, for example by forming several parallel gates.
  • the doping level of the peripheral parts of the region 16 P in contact with the trenches 22 may be lower than at the centre of the region 16 P, in particular when the dopant atoms are boron and when the insulator of the trenches is silicon oxide.
  • These more lightly doped peripheral regions are indicated by the reference 54 in FIG. 2H .
  • the gate insulator 30 is thicker in the regions 52 surmounting the regions 54 than in the central regions, since the threshold voltage increases when the thickness of the gate insulator increases.
  • the properties of the regions 54 are generally not identical in transistors designed to be identical, and this results in differences between the threshold voltages of the peripheral regions of the various transistors. The regions 52 make it possible to partly compensate these differences.
  • the parameters of the method in particular the thicknesses of the layers 20 , 40 and 42 , and of the possible layer 14 , and the steps of etching the insulator of the trenches of FIGS. 2E, 2F and of cleaning of FIG. 2G , can be tailored so as to obtain at one and the same time optimal electrical characteristics for the P-channel transistor and for the N-channel transistor, and/or to obtain particularly reduced differences between transistors designed to be identical.
  • a thermal oxidation (not represented) can furthermore be undertaken, making it possible to obtain a layer 14 solely on the side of the region 16 N, or to obtain a thicker layer 14 on the region 16 N than on the region 16 P.
  • This thermal oxidation is then tailored together with the other parameters of the method so as to optimize the electrical characteristics of the transistors and/or reduce the differences between transistors designed to be identical.
  • optimized N-channel and P-channel transistors are obtained simultaneously, in a simple manner and in a particularly reduced number of steps. Furthermore, in the case where regions 52 are provided, the advantage of reliability of the method of FIGS. 1A to 1F is preserved, related to the fact that the regions 52 are auto-aligned.
  • an N-channel transistor and a P-channel transistor exhibiting particularly low leakage currents, even for small transistors, are obtained simultaneously. This results in particularly low energy consumption, in particular for a chip comprising such transistors.
  • this method when using this method to produce, in addition to the P-channel transistor, several N-channel transistors designed to be identical, N-channel transistors whose electrical characteristics are quasi-identical, including under cold operation, are obtained. Therefore, this method exhibits particular interest in respect of the production of transistors intended to be used in a measurement device. Furthermore, this results in particularly high fabrication efficiency.
  • the method may be adapted for the simultaneous production of transistors which differ for example by their gate insulator thickness and/or by their gate insulator materials.
  • the gate insulator layer 30 formed in the step of FIG. 2H may have thicknesses and/or be made of materials which differ at the locations of the various transistors. It is thus possible to obtain transistors which differ by their threshold voltages and/or their voltages of use.
  • the transistors can then be of the same channel type, although the production of P-channel and N-channel transistors has been described.
  • the embodiments described hereinabove relate to the fabrication of transistors, the methods described can be adapted for the fabrication of other components, for example for the fabrication of memory points.
  • the gates of the transistors are covered with an insulating layer, not represented, this insulating layer comprising for example a silicon nitride layer between two silicon oxide layers, and a gate (not represented) is formed on this insulating layer.
  • This gate thus constitutes a control gate for the memory point, the gate 32 constituting a floating gate of the memory point.
  • a transistor and another component, such as a memory point can also be formed simultaneously.
  • the two components may be of the same channel type or of different channel types.

Abstract

A method can be used for fabricating first and second semiconductor regions separated by isolating trenches. A semiconductor substrate is covered with a first silicon nitride layer. The first region is covered with a protection layer that can be etched selectively with respect to the silicon nitride. The structure is covered with a second silicon nitride layer. The trenches are etched through the second and first silicon nitride layers and filled with a filling silicon oxide to a level situated above the protection layer. The second silicon nitride layer and the part of the first silicon nitride layer situated on the second region are selectively removed and the protection layer is removed. The filling oxide is selectively etched by wet etching, thus resulting in pits on the surface of the filling oxide around the second region.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This application is a continuation of U.S. application Ser. No. 15/992,481, filed on May 30, 2018, which claims priority to French Patent Application No. 1756181, filed on Jun. 30, 2017, which applications are hereby incorporated herein by reference.
  • This application is related to U.S. patent application Ser. No. 15/993,922, filed on May 31, 2018 (now U.S. Pat. No. 10,553,499), which claims priority to French Patent Application No. 1755226.
    • TECHNICAL FIELD
  • The present patent application relates to a method for producing semiconductor regions in an electronic chip.
    • BACKGROUND
  • Diverse problems can arise in an electronic chip comprising field-effect transistors.
  • In particular, one problem in such transistors is that, in general, the smaller the transistors, the higher, in relative value, the leakage current. This results in high energy consumption.
  • Another problem is that transistors designed to be identical in fact generally exhibit different electrical characteristics, in particular different threshold voltages. The differences between these electrical characteristics usually tend to get worse when the operating temperature decreases. This results in diverse difficulties in actually obtaining the envisaged electrical characteristics. These difficulties arise particularly in the case where the chip is provided for analogue operation, for example in a measurement device, and/or for cold operation, for example at negative ambient temperature. This usually leads to certain chips being rejected during post-fabrication checking.
  • Moreover, an electronic chip can comprise memory points of floating gate transistor type, surmounted by a control gate. In addition to the above-mentioned problems in respect of the transistors, such memory points exhibit problems of degradation of the transistor's gate insulator due to the fact that relatively high programming voltages are required to be applied.
  • The diverse known methods for solving the diverse problems mentioned hereinabove require numerous fabrication steps if it is desired to implement them simultaneously for different types, N-channel and P-channel, of transistors and/or of memory points.
    • SUMMARY
  • The present patent application relates to a method for producing semiconductor regions in an electronic chip. Particular embodiments relate to semiconductor regions intended for the formation of N-channel and P-channel transistors and/or memory points, and a device comprising such regions. Embodiments can mitigate all or some of the drawbacks described above.
  • Thus, one embodiment provides a method for fabricating first and second semiconductor regions separated by isolating trenches. A semiconductor substrate is covered with a first silicon nitride layer. The first region is covered with a protection layer that can be etched selectively with respect to the silicon nitride. The structure is covered with a second silicon nitride layer. The trenches are etched through the second and first silicon nitride layers and filled with a filling silicon oxide to a level situated above the protection layer. The second silicon nitride layer and the part of the first silicon nitride layer situated on the second region are selectively removed and the protection layer is removed. The filling oxide is selectively etched by wet etching, thus resulting in pits on the surface of the filling oxide around the second region. The part of the first silicon nitride layer situated on the first region is selectively removed.
  • According to one embodiment, the protection layer is a first silicon oxide layer and the protection layer is removed selectively by the said wet etching.
  • According to one embodiment, the method further comprises cleaning the structure.
  • According to one embodiment, the method further comprises the formation of a second silicon oxide layer on the substrate. The second silicon oxide layer can be removed when the structure is cleaned.
  • According to one embodiment, the trenches are filled with the filling oxide to a level situated above the second silicon nitride layer. The portions of the structure that are situated above the part of the second silicon nitride layer situated on the second region are removed by chemical-mechanical polishing. The oxide filling can be selectively etched.
  • According to one embodiment, the trenches are filled to a level between 2 and 15 nm above the protection layer.
  • According to one embodiment, after filling the trenches, the second silicon nitride layer has in the first region a thickness of between 30 and 100 nm.
  • According to one embodiment, the protection layer has a thickness of between 2 and 20 nm.
  • According to one embodiment, the method further comprises forming by thermal oxidation a third silicon oxide layer on the second region. The third silicon oxide layer can be removed when the protection layer is removed.
  • According to one embodiment, the substrate is the upper semiconductor layer of an SOI structure.
  • According to one embodiment, the substrate is a bulk substrate.
  • One embodiment provides the method hereinabove for the simultaneous fabrication of an N-channel transistor and of a P-channel transistor. The method includes P-type doping the first region and N-type doping the second region. After selectively removing the part of the first silicon nitride layer situated on the first region, the N-channel transistor is formed in and on the first region and the P-channel transistor is formed in and on the second region.
  • One embodiment provides a device comprising first and second semiconductor regions separated by trenches filled with an insulator. The surface of the insulator has, around the second region, a shape in the form of pits and, around the first region, a shape which is different from the shape around the second region.
  • One embodiment provides an electronic chip comprising the device hereinabove, an N-channel transistor situated in and on the first region, and a P-channel transistor situated in and on the second region.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • These features and advantages, along with others, will be presented in detail in the following description of particular embodiments, provided without limitation and in relation to the appended figures among which:
  • FIGS. 1A to 1E are partial and schematic sectional views illustrating steps of a method for fabricating a P-channel transistor;
  • FIG. 1F is a schematic view from above of the structure of FIG. 1E;
  • FIGS. 2A to 2H are partial and schematic sectional views illustrating steps of an embodiment of a method for fabricating an N-channel transistor and a P-channel transistor; and
  • FIG. 2I is a schematic view from above of the structure of FIG. 2H.
    •  DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
  • The various figures have not been drawn to scale and, in addition, in the various figures, elements that are the same have been referenced by the same references. For the sake of clarity, only those elements which are useful to the comprehension of the described embodiments have been shown and are described in detail. In particular, diverse elements of the transistors, such as spacers, are not represented.
  • In the description which follows, when making reference to position qualifiers such as the terms, “left”, “right”, “above”, “upper”, “lower”, etc., or to orientation qualifiers such as the terms “horizontal” or “vertical”, reference is made to the orientation of the element concerned in the figures considered, it being understood that, in practice, the devices described may be oriented differently.
  • FIGS. 1A to 1E are partial and schematic sectional views illustrating steps of a method for fabricating a P-channel transistor.
  • In the step of FIG. 1A, a semiconductor substrate 10 comprises by way of example an N-type doped well 12N. In the upper part of the well 12N, an N-type doped region 16N has been formed, and its doping level has been selected as a function of the desired electrical characteristics of the transistor. By way of variant, the well 12N and the region 16N will be doped in later steps of the method. The substrate is covered with a fine silicon oxide layer 14, of thickness typically between 2 and 20 nm. A silicon nitride layer 20 is thereafter deposited on the structure, and then trenches 22 passing through the silicon nitride are etched (only halves of the trenches are visible in the figures). The trenches penetrate into the substrate and delimit a portion of the region 16N.
  • In the step of FIG. 1B, the trenches are filled with an insulator, for example silicon oxide, and then a planarization is carried out as far as the upper level of the silicon nitride 20.
  • In the step of FIG. 1C, the insulator of the trenches 22 is selectively etched with respect to the silicon nitride 20, for example to a level situated above the region 16N.
  • In the step of FIG. 1D, the silicon nitride is removed by selective etching with respect to the insulator of the trenches 22. The structure is thereafter cleaned, so as to eliminate the oxide of the layer 14, still present on the region 16N. This cleaning is, for example, carried out in a solution based on hydrofluoric acid. This cleaning causes the formation of an annular pit 28 on the surface of the insulator of the trenches around the region 16N.
  • In the step of FIG. 1E, a P-channel MOS transistor is formed in and on the region 16N. In particular, a gate insulator layer 30 and a gate 32 are formed.
  • FIG. 1F is a view from above of the structure of FIG. 1E. The insulating layer 30 is not represented. Viewed from above, the gate 32 extends over the width of the region 16N. Drain and source regions 34 have been formed on each side of the gate.
  • The parameters of the method hereinabove, in particular the etching of the insulator of the trenches 22 in the step of FIG. 1C and the cleaning in the step of FIG. 1D, have been adjusted so as to optimize the electrical characteristics of the transistor, for example to minimize its leakage current. This adjustment is for example carried out by trials. Indeed, the electrical characteristics, such as the threshold voltage and the leakage current, are different at the edges and at the center of the transistor because of diverse edge effects. Adjusting the parameters of the method makes it possible to obtain a pit shape which reduces these edge effects.
  • A method making it possible to obtain a P-channel transistor of optimal electrical characteristics has been described hereinabove. However, this method is not suitable for obtaining an N-channel transistor of optimal electrical characteristics. Indeed, the edge effects are different in the N-channel transistor and in the P-channel transistor. In particular, when the N-type region 16N is replaced by a P-type region 16P, the dopant atoms tend to migrate in the insulator of the trenches in the course of diverse annealings provided for in the method, especially when dealing with boron atoms and trenches filled with silicon oxide. It follows from this that the doping level of the region 16P is lower at the edges of the transistor than at the center of the transistor. Thus, the pit shape obtained in the P-channel transistor is not the shape which makes it possible to minimize the edge effects of the N-channel transistor.
  • FIGS. 2A to 2H are partial and schematic sectional views illustrating steps of an embodiment of a method for fabricating an N-channel transistor on the left side of the figures and of a P-channel transistor on the right side. This method makes it possible to optimize the electrical characteristics of the P-channel transistors and of the N-channel transistors.
  • In the step of FIG. 2A, a substrate 10 has been provided. The substrate 10 is here by way of example a bulk semiconductor substrate, of silicon for example. The left part of the substrate portion represented is a P-type doped well 12P. The right part of the substrate portion represented is an N-type doped well 12N. By way of variant, the substrate may be a semiconductor layer covering an insulating layer on a support, that is to say the upper semiconductor layer of an SOI (“Silicon On Insulator”) structure.
  • Preferably, on the left side, a P-type doped layer 16P′, and, on the right side, an N-type doped layer 16N′, are implanted in the substrate. The doping levels of the layer 16P′ and of the layer 16N′ are, for example, greater than 1017 atoms/cm3. In the variant where the substrate is a thin layer of monocrystalline silicon covering the insulating layer of an SOI structure, the layers 16P′ and 16N′ can extend throughout the thickness of the thin monocrystalline silicon layer.
  • By way of variant, the well 12P, the well 12N, the layer 16P′ and/or the layer 16N′, instead of being doped starting from the step of FIG. 2A, may be doped in later steps of the method.
  • Preferably, the substrate is covered with a silicon oxide layer 14 of thickness for example of between 2 and 20 nm.
  • After this, a silicon nitride layer 20 covering the structure is formed. The thickness of the layer 20 is, for example, between 30 and 100 nm.
  • Thereafter, a layer 40 of a material that can be etched selectively with respect to the silicon nitride, for example silicon oxide, is formed only on the layer 16P′. The layer 40 preferably has a thickness of between 2 and 20 nm. The function of the layer 40 will subsequently be to protect the silicon nitride layer 20.
  • In the step of FIG. 2B, the structure is covered with a silicon nitride layer 42. The thickness of the layer 42 is for example between 30 and 100 nm. It follows from this that the silicon nitride layers 20 and 42 are directly on one another on the side of the region 16N′, and are separated by the layer 40 on the side of the region 16P′.
  • In the step of FIG. 2C, trenches 22 are etched, passing all the way through, on the left side, the two silicon nitride layers 20 and 42 and the region 16P′, and, on the right side, the layers 20, 40 and 42 and the region 16N′. The trenches 22 delimit a semiconductor region 16P in the layer 16P′ and a semiconductor region 16N in the layer 16N′. The trenches 22 surround the regions 16P and 16N.
  • In the step of FIG. 2D, the trenches 22 are filled with an insulator, for example silicon oxide. By way of example, the whole of the structure is covered with this insulator to a level situated above that of the silicon nitride layer 42, and a chemical-mechanical polishing is undertaken thereafter. The polishing removes the parts of the structure which are situated above the upper level of the silicon nitride covering the region 16N, or above a level situated in the silicon nitride layer 42. After polishing, the silicon nitride of the layer 42 is flush with the surface of the insulator of the trenches, and the layer 42 has on the side of the region 16P a thickness of for example between 30 and 100 nm.
  • In the step of FIG. 2E, the insulator of the trenches 22 is etched selectively to a level situated above that of the protection layer 40, for example by a hydrofluoric acid solution or one based on hydrofluoric acid. By way of example, the surface of the insulator of the trenches after etching is situated between 2 and 15 nm above the upper surface of the protection layer 40.
  • In the step of FIG. 2F, a selective etching of the silicon nitride is performed, for example by a phosphoric acid solution or one based on phosphoric acid. On the side of the region 16N, the silicon nitride of the two layers 20 and 42 is removed. On the side of the region 16P, the silicon nitride of the layer 42 is removed, but the silicon nitride of the layer 20 is not removed, since it is protected by the layer 40.
  • The insulator of the trenches is thereafter etched and the protection layer 40 is removed, for example, by a hydrofluoric acid solution or one based on hydrofluoric acid. The etching is continued until the level of the insulator of the trenches, dependent on the desired characteristics of the transistors, is for example between 20 nm below and 30 nm above the regions 16N and 16P. The possible layer 14 is removed in this step on the side of the region 16N. This etching forms an annular pit 28 on the surface of the insulator of the trenches around the region 16N. Due to the presence of the silicon nitride of the layer 20 above the region 16P, the etching is not accompanied by pit formation around the region 16P.
  • In the step of FIG. 2G, the silicon nitride of the layer 20 is selectively removed on the region 16P, for example by a solution based on phosphoric acid. A cleaning is undertaken thereafter, for example by a hydrofluoric acid solution or one based on hydrofluoric acid. The possible layer 14 is thus removed on the side of the region 16P. This step further hollows out the pits 28 around the regions 16N. Around the regions 16P, the surface of the insulator of the trenches 22 has a different shape from that of the pits 28. By way of example, starting from the edge of the region 16P, the surface meets up with the upper level of the insulator of the trenches via slopes 50.
  • In the step of FIG. 2H, the N-channel and P-channel transistors in and on respectively the regions 16P and 16N are produced. In particular, a gate insulator layer 0 and the gates 32 are formed. By way of example, the gate insulator 30 is formed by thermal oxidation and/or by deposition. The gate insulator can comprise a material with high dielectric permittivity such as, for example, hafnium oxide. By way of example, the gate insulator is deposited in a compliant manner, and thus, on the side of the region 16P, in a part 52 situated on the slopes 50 (approximately plumb with the edges of the region 16P), the thickness, taken vertically, of the gate insulator is greater than that of the gate insulator in the horizontal parts (that is to say central parts situated above a central part of the region 16P).
  • FIG. 2I is a schematic view from above of the structure of FIG. 2H, in which the gate insulator is not represented. The gates 32 extend across the regions 16P and 16N between drain and source regions 34. In the case of transistors formed side by side, the gate may be common to two transistors. By way of example, a single transistor has been represented in and on each of the regions 16P and 16N, but it is possible to form several transistors on each of the regions 16P and 16N, for example by forming several parallel gates.
  • As indicated previously, when the channel region of the transistor is a P-type region 16P, the doping level of the peripheral parts of the region 16P in contact with the trenches 22 may be lower than at the centre of the region 16P, in particular when the dopant atoms are boron and when the insulator of the trenches is silicon oxide. These more lightly doped peripheral regions are indicated by the reference 54 in FIG. 2H. This results in a lower threshold voltage of the transistor in these peripheral regions than in the central regions with homogeneous doping. This is compensated in part or entirely by the fact that the gate insulator 30 is thicker in the regions 52 surmounting the regions 54 than in the central regions, since the threshold voltage increases when the thickness of the gate insulator increases. Moreover, the properties of the regions 54 are generally not identical in transistors designed to be identical, and this results in differences between the threshold voltages of the peripheral regions of the various transistors. The regions 52 make it possible to partly compensate these differences.
  • The parameters of the method, in particular the thicknesses of the layers 20, 40 and 42, and of the possible layer 14, and the steps of etching the insulator of the trenches of FIGS. 2E, 2F and of cleaning of FIG. 2G, can be tailored so as to obtain at one and the same time optimal electrical characteristics for the P-channel transistor and for the N-channel transistor, and/or to obtain particularly reduced differences between transistors designed to be identical. Optionally, in the step of FIG. 2F, after removal of the silicon nitride unprotected by the layer 40 and before etching of the layer 40 and of the insulator of the trenches, a thermal oxidation (not represented) can furthermore be undertaken, making it possible to obtain a layer 14 solely on the side of the region 16N, or to obtain a thicker layer 14 on the region 16N than on the region 16P. This thermal oxidation is then tailored together with the other parameters of the method so as to optimize the electrical characteristics of the transistors and/or reduce the differences between transistors designed to be identical.
  • According to one advantage, optimized N-channel and P-channel transistors are obtained simultaneously, in a simple manner and in a particularly reduced number of steps. Furthermore, in the case where regions 52 are provided, the advantage of reliability of the method of FIGS. 1A to 1F is preserved, related to the fact that the regions 52 are auto-aligned.
  • According to another advantage, an N-channel transistor and a P-channel transistor exhibiting particularly low leakage currents, even for small transistors, are obtained simultaneously. This results in particularly low energy consumption, in particular for a chip comprising such transistors.
  • According to another advantage, when using this method to produce, in addition to the P-channel transistor, several N-channel transistors designed to be identical, N-channel transistors whose electrical characteristics are quasi-identical, including under cold operation, are obtained. Therefore, this method exhibits particular interest in respect of the production of transistors intended to be used in a measurement device. Furthermore, this results in particularly high fabrication efficiency.
  • Particular embodiments have been described. Diverse variants and modifications will be apparent to those skilled in the art. In particular, the method may be adapted for the simultaneous production of transistors which differ for example by their gate insulator thickness and/or by their gate insulator materials. For this purpose the gate insulator layer 30 formed in the step of FIG. 2H may have thicknesses and/or be made of materials which differ at the locations of the various transistors. It is thus possible to obtain transistors which differ by their threshold voltages and/or their voltages of use. Moreover, the transistors can then be of the same channel type, although the production of P-channel and N-channel transistors has been described.
  • Furthermore, although the embodiments described hereinabove relate to the fabrication of transistors, the methods described can be adapted for the fabrication of other components, for example for the fabrication of memory points. Accordingly, in the step of FIG. 2H, the gates of the transistors are covered with an insulating layer, not represented, this insulating layer comprising for example a silicon nitride layer between two silicon oxide layers, and a gate (not represented) is formed on this insulating layer. This gate thus constitutes a control gate for the memory point, the gate 32 constituting a floating gate of the memory point. By way of variant, a transistor and another component, such as a memory point, can also be formed simultaneously. The two components may be of the same channel type or of different channel types.

Claims (22)

What is claimed is:
1. A method of fabricating a semiconductor device, the method comprising:
forming a structure at a surface of a semiconductor body, the structure including a first region and a second region that are separated by a filling material and a covering layer overlying the first region and the second region, wherein the covering layer comprises a first covering material over the first region and a second covering material over the second region;
etching the covering layer so that all of the second covering material is removed from over the second region but not all of the first covering material is removed from over the first region so that pits are formed on the surface of the filling material around the second region, wherein the pits comprise regions on the surface of the filling material that extend below a top surface of the second region;
removing remaining portions of the first covering material from over the first region; and
forming an N-channel transistor in and on the first region and a P-channel transistor in and on the second region.
2. The method according to claim 1, wherein forming the structure at the surface of the semiconductor body comprises forming the covering layer by:
covering the first and second regions with a first silicon nitride layer;
covering the first region with a protection layer that can be etched selectively with respect to silicon nitride; and
forming a second silicon nitride layer over the protection layer.
3. The method according to claim 2, wherein the protection layer comprises a first silicon oxide layer.
4. The method according to claim 3, wherein the protection layer is removed selectively by wet etching.
5. The method according to claim 2, wherein the protection layer has a thickness of between 2 and 20 nm.
6. The method according to claim 2, further comprising doping the first region with p-type dopants type and doping the second region with n-type dopants prior to covering the semiconductor body with the first silicon nitride layer.
7. The method according to claim 2, wherein etching the covering layer comprises:
etching trenches through the second and first silicon nitride layers and into the semiconductor body;
filling the trenches with a filling oxide to a level above an upper surface of the protection layer;
selectively removing the second silicon nitride layer and first silicon nitride layer disposed over the second region;
removing the protection layer; and
selectively etching the filling oxide by wet etching so that the pits are formed on a surface of the filling oxide around the second region.
8. The method according to claim 7, wherein the second silicon nitride layer over the first region has a thickness of between 30 and 100 nm after the trenches are filled.
9. The method according to claim 7, wherein removing remaining portions of the first covering material comprises selectively removing the first silicon nitride layer disposed over the first region.
10. The method according to claim 9, wherein selectively etching the filling oxide comprises performing an etch process using an etchant based on hydrofluoric acid, and wherein selectively removing the second silicon nitride layer and first silicon nitride layer comprises performing an etch process using an etchant based on phosphoric acid.
11. The method according to claim 9, further comprising performing a cleaning step after selectively removing the first silicon nitride layer disposed over the first region.
12. The method according to claim 11, further comprising forming a second silicon oxide layer prior to covering the semiconductor body with the first silicon nitride layer, the second silicon oxide layer being removed by the cleaning step.
13. The method according to claim 7, wherein filling the trenches comprises:
filling the trenches with the filling oxide to a level above the second silicon nitride layer;
chemical-mechanical polishing portions of the filling oxide that are located above a part of the second silicon nitride layer over the second region; and
selectively etching the filling oxide.
14. The method according to claim 7, wherein filling the trenches comprises filling the trenches with a filling silicon oxide to a level between 2 and 15 nm above the upper surface of the protection layer.
15. The method according to claim 7, further comprising, before selectively removing the second silicon nitride layer and after removing the protection layer and selectively etching the filling oxide, performing a thermal oxidation to form a third silicon oxide layer on the second region.
16. The method according to claim 15, the third silicon oxide layer being removed when the protection layer is removed.
17. The method according to claim 1, wherein the semiconductor body is an upper semiconductor layer of an SOI structure.
18. The method according to claim 1, wherein the semiconductor body is a bulk substrate.
19. A method of fabricating a semiconductor device, the method comprising:
forming a sacrificial structure at a surface of an upper semiconductor layer of an SOI structure that has a first region and a second region, the sacrificial structure comprising a sandwich layer overlying the first region but not the second region, the sandwich layer comprising a protective layer sandwiched between layers of material having the same etch properties;
forming an isolation trench after the fabrication of the sacrificial structure, the isolation trench extending into the semiconductor layer at a location between the first region and the second region;
filling the isolation trench with an insulating material;
removing the sacrificial structure so that the insulating material filling the isolation trench extends to a level above edges of the first region at a location adjacent the edges of the first region and so that the insulating material filling the isolation trench extends to a level below edges of the second region at a location adjacent the edges of the second region;
forming a first gate dielectric layer over the first region;
forming a second gate dielectric layer over the second region;
forming a first gate region over and insulated from the first region by the first gate dielectric layer, the first gate region spaced from the edges of the first region by the insulating material; and
forming a second gate region over and insulated from the second region by the second gate dielectric layer.
20. The method according to claim 19, wherein the first and second gate dielectric layers comprise hafnium oxide.
21. A method of fabricating a semiconductor device, the method comprising:
forming a first layer over a semiconductor body that includes a first region and a second region, the first and second regions each having an upper portion doped at doping greater than 1017 atoms/cm3, wherein the first layer comprises a first nitride layer;
forming a second layer over the first layer, wherein the second layer comprises a first oxide layer;
forming a third layer over a portion of the second layer, the third layer overlying the first region but not the second region of the semiconductor body, wherein the third layer comprises a second nitride layer;
forming a fourth layer, the fourth layer overlying the third layer over the first region and overlying the second layer over the second region, wherein fourth layer comprises a second oxide layer;
etching a trench through the first, second, third and fourth layers and into the semiconductor body at a location between the first region and the second region;
filling the trench with an insulating material;
performing an etching process using an etchant based on phosphoric acid to expose the second region of the semiconductor body, the first region of the semiconductor body being covered by a portion of the first layer and a portion of the second layer;
after performing the etching process, removing the portion of the first layer and the portion of the second layer to expose the first region of the semiconductor body, the portion being removed using an etchant based on hydrofluoric acid; and
forming a dielectric layer over the first and second regions, the dielectric layer comprising hafnium oxide.
22. The method according to claim 21, wherein the insulating material that fills the trench is filled to a level above edges of the first region at a location adjacent edges of the first region.
US16/860,392 2017-06-30 2020-04-28 Production of semiconductor regions in an electronic chip Abandoned US20200258773A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16/860,392 US20200258773A1 (en) 2017-06-30 2020-04-28 Production of semiconductor regions in an electronic chip

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
FR1756181 2017-06-30
FR1756181A FR3068507B1 (en) 2017-06-30 2017-06-30 REALIZATION OF SEMICONDUCTOR REGIONS IN AN ELECTRONIC CHIP
US15/992,481 US10672644B2 (en) 2017-06-30 2018-05-30 Production of semiconductor regions in an electronic chip
US16/860,392 US20200258773A1 (en) 2017-06-30 2020-04-28 Production of semiconductor regions in an electronic chip

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US15/992,481 Continuation US10672644B2 (en) 2017-06-30 2018-05-30 Production of semiconductor regions in an electronic chip

Publications (1)

Publication Number Publication Date
US20200258773A1 true US20200258773A1 (en) 2020-08-13

Family

ID=60138477

Family Applications (2)

Application Number Title Priority Date Filing Date
US15/992,481 Active US10672644B2 (en) 2017-06-30 2018-05-30 Production of semiconductor regions in an electronic chip
US16/860,392 Abandoned US20200258773A1 (en) 2017-06-30 2020-04-28 Production of semiconductor regions in an electronic chip

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US15/992,481 Active US10672644B2 (en) 2017-06-30 2018-05-30 Production of semiconductor regions in an electronic chip

Country Status (3)

Country Link
US (2) US10672644B2 (en)
CN (2) CN109216281B (en)
FR (1) FR3068507B1 (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3067516B1 (en) 2017-06-12 2020-07-10 Stmicroelectronics (Rousset) Sas REALIZATION OF SEMICONDUCTOR REGIONS IN AN ELECTRONIC CHIP
FR3068507B1 (en) * 2017-06-30 2020-07-10 Stmicroelectronics (Rousset) Sas REALIZATION OF SEMICONDUCTOR REGIONS IN AN ELECTRONIC CHIP
US11469302B2 (en) 2020-06-11 2022-10-11 Atomera Incorporated Semiconductor device including a superlattice and providing reduced gate leakage
US11569368B2 (en) * 2020-06-11 2023-01-31 Atomera Incorporated Method for making semiconductor device including a superlattice and providing reduced gate leakage

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3967440B2 (en) * 1997-12-09 2007-08-29 株式会社ルネサステクノロジ Manufacturing method of semiconductor integrated circuit device
US20040065937A1 (en) * 2002-10-07 2004-04-08 Chia-Shun Hsiao Floating gate memory structures and fabrication methods
JP4811901B2 (en) * 2004-06-03 2011-11-09 ルネサスエレクトロニクス株式会社 Semiconductor device
US7282402B2 (en) * 2005-03-30 2007-10-16 Freescale Semiconductor, Inc. Method of making a dual strained channel semiconductor device
JP5400378B2 (en) * 2006-06-30 2014-01-29 富士通セミコンダクター株式会社 Semiconductor device and method for manufacturing semiconductor device
JP2011066188A (en) * 2009-09-17 2011-03-31 Toshiba Corp Semiconductor device, and method for manufacturing the same
US8563394B2 (en) * 2011-04-11 2013-10-22 International Business Machines Corporation Integrated circuit structure having substantially planar N-P step height and methods of forming
US8778772B2 (en) * 2012-01-11 2014-07-15 Globalfoundries Inc. Method of forming transistor with increased gate width
US8871586B2 (en) * 2012-10-18 2014-10-28 Globalfoundries Inc. Methods of reducing material loss in isolation structures by introducing inert atoms into oxide hard mask layer used in growing channel semiconductor material
FR3067516B1 (en) * 2017-06-12 2020-07-10 Stmicroelectronics (Rousset) Sas REALIZATION OF SEMICONDUCTOR REGIONS IN AN ELECTRONIC CHIP
FR3068507B1 (en) * 2017-06-30 2020-07-10 Stmicroelectronics (Rousset) Sas REALIZATION OF SEMICONDUCTOR REGIONS IN AN ELECTRONIC CHIP

Also Published As

Publication number Publication date
US20190006229A1 (en) 2019-01-03
FR3068507B1 (en) 2020-07-10
FR3068507A1 (en) 2019-01-04
CN208548342U (en) 2019-02-26
CN109216281B (en) 2023-05-23
CN109216281A (en) 2019-01-15
US10672644B2 (en) 2020-06-02

Similar Documents

Publication Publication Date Title
US20200258773A1 (en) Production of semiconductor regions in an electronic chip
US7767546B1 (en) Low cost fabrication of double box back gate silicon-on-insulator wafers with built-in shallow trench isolation in back gate layer
US7528453B2 (en) Field effect transistor with local source/drain insulation and associated method of production
US10170475B2 (en) Silicon-on-nothing transistor semiconductor structure with channel epitaxial silicon region
US10038075B2 (en) Silicon-on-nothing transistor semiconductor structure with channel epitaxial silicon-germanium region
US7262109B2 (en) Integrated circuit having a transistor level top side wafer contact and a method of manufacture therefor
US8476131B2 (en) Methods of forming a semiconductor device with recessed source/design regions, and a semiconductor device comprising same
US20100176495A1 (en) Low cost fabrication of double box back gate silicon-on-insulator wafers
US11329067B2 (en) Co-integration of bulk and SOI transistors
JP2008533705A (en) Fabrication of carrier substrate contacts to trench-isolated SOI integrated circuits with high voltage components
US20120025267A1 (en) Mos device for eliminating floating body effects and self-heating effects
US11121042B2 (en) Production of semiconductor regions in an electronic chip
US10770547B2 (en) Integrated circuit comprising components, for example NMOS transistors, having active regions with relaxed compressive stresses
US10332808B2 (en) Device comprising multiple gate structures and method of simultaneously manufacturing different transistors
US10777552B2 (en) Method of simultaneous fabrication of SOI transistors and of transistors on bulk substrate
US8530292B2 (en) Method for manufacturing a strained channel MOS transistor
US20210175346A1 (en) Mos transistor spacers and method of manufacturing the same
EP3671860A1 (en) Semiconductor transistor device and method of manufacturing the same
US20130328159A1 (en) Implementing isolated silicon regions in silicon-on-insulator (soi) wafers using bonded-wafer technique

Legal Events

Date Code Title Description
STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

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: NON FINAL ACTION MAILED

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

STPP Information on status: patent application and granting procedure in general

Free format text: ADVISORY ACTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION