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
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/02104—Forming layers
  • H01L21/02365—Forming inorganic semiconducting materials on a substrate
  • H01L21/02656—Special treatments
  • H01L21/02664—Aftertreatments
  • H01L21/02667—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
  • H01L21/02672—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth using crystallisation enhancing elements
• • 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
  • H01L21/02365—Forming inorganic semiconducting materials on a substrate
  • H01L21/02518—Deposited layers
  • H01L21/02521—Materials
  • H01L21/02524—Group 14 semiconducting materials
  • H01L21/02532—Silicon, silicon germanium, germanium
• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B1/00—Single-crystal growth directly from the solid state
  • C30B1/02—Single-crystal growth directly from the solid state by thermal treatment, e.g. strain annealing
  • C30B1/023—Single-crystal growth directly from the solid state by thermal treatment, e.g. strain annealing from solids with amorphous structure
• • C—CHEMISTRY; METALLURGY
  • C30—CRYSTAL GROWTH
  • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
  • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
  • C30B29/02—Elements
  • C30B29/06—Silicon
• • 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
  • H01L21/02365—Forming inorganic semiconducting materials on a substrate
  • H01L21/02367—Substrates
  • H01L21/0237—Materials
  • H01L21/02373—Group 14 semiconducting materials
  • H01L21/02381—Silicon, silicon germanium, germanium
• • 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
  • H01L21/02365—Forming inorganic semiconducting materials on a substrate
  • H01L21/02518—Deposited layers
  • H01L21/02587—Structure
  • H01L21/0259—Microstructure
  • H01L21/02595—Microstructure polycrystalline

Definitions

• This invention relates to the crystallisation of amorphous silicon.
• Figure 1 shows a plan view taken after fifteen minutes anneal, with a diffraction inset showing amorphous material. One minute later, rapid crystallisation occurred resulting in micron size crystal formation, see Figure 2. Area A, as seen in Figure 3, is a large single crystal as can be seen from the diffraction pattern.
• a number of black contamination spots are visible on all of the plan view figures relating to in situ-heating, and serve as position markers. Their presence is normal.
• TEM, XTEM and SEM were used to characterise the crystallisation resulting from annealing amorphous silicon (a-Si ) films prepared using Plasma Enhanced Chemical Vapour Deposition (PECVD) overlying a thin gold film on a thermally-oxidised silicon base.
• a-Si amorphous silicon
• PECVD Plasma Enhanced Chemical Vapour Deposition
• the a-Si thickness was estimated as l ⁇ m and the gold thickness as O.l ⁇ m.
• the a-Si was hydrogenated during deposition.
• Sample A is as described above.
• Sample B the gold was distributed in an array of 50 ⁇ diameter dots in a lattice of several millimetres spacing.
• Sample C was the control sample in which no gold was present.
• Samples A, B and C were annealed at 600°C for 24hrs in a furnace after being sealed in an evacuated ampoule.
• the film was completely amorphous.
• a gold layer was present.
• Gold dots Annealed at 600°C for 24 hrs.
• the microstructure was mostly a-Si with areas of defective mosaic polysilicon. SEM impression (secondary image, no tilt, cleaning or coating).
• Films of amorphous silicon of thickness 300nm were deposited onto silicon wafers by LPCVD, rather than PECVD as used before, in order to reduce the hydrogen content and thereby reduce the damage to the film from hydrogen evolution during the anneal/crystallisation. These films were cleaned by plasma etching and then coated with 60nm of gold. Samples were taken from these wafers and were placed in quartz ampoules which were evacuated and then annealed for 24 hours, some at 500°C and some at 600°C.
• FIGS 11,12 are cross sectional TEMs from the hazy areas of the sample which show that a film of pure silicon has been formed over the surface of the sample and a gold/silicon alloy nearest the substrate. Between pure silicon film and the gold/silicon alloy is a thin interlayer about 1.5nm thick. In addition, a number of small gold particles remain on the surface of the sample.
• FIG. 13 A plan view micrograph (Figure 13) from the same area shows a mixture of silicon and gold crystallites, but diffraction patterns from the film reveal the presence of substantial single crystalline areas (see insets to Figures 11 and 13). This is attributed to the "single" crystalline silicon overlayer, which is clearly revealed by the cross sectional mi rographs.
• the gold in order for this process to occur, the gold must be in intimate contact with the amorphous silicon, i.e. intermediate contamination layers of, for example, native oxide must not be present or must be very thin. Except in so far as it may affect the nature of any intermediate layers, it does not matter whether the gold is on top of the silicon or vice versa. Both positions have been shown to be effective.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• General Physics & Mathematics (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Thermal Sciences (AREA)
• Recrystallisation Techniques (AREA)

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• 1990
  • 1990-07-03 GB GB909014723A patent/GB9014723D0/en active Pending
• 1991
  • 1991-07-03 EP EP91912797A patent/EP0489900A1/de not_active Withdrawn
  • 1991-07-03 WO PCT/GB1991/001086 patent/WO1992001089A1/en not_active Application Discontinuation
  • 1991-07-03 GB GB9114398A patent/GB2245552A/en not_active Withdrawn
  • 1991-07-03 JP JP3512016A patent/JPH05501701A/ja active Pending

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