Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/38—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials characterised by treatments done after the formation of the materials
  • H10P14/3802—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
  • H10P14/3808—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth using laser beams
  • H10P14/3814—Continuous wave laser beam
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/38—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials characterised by treatments done after the formation of the materials
  • H10P14/3802—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
  • H10P14/3808—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth using laser beams
• • 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
  • C30B13/00—Single-crystal growth by zone-melting; Refining by zone-melting
• • 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
  • C30B13/00—Single-crystal growth by zone-melting; Refining by zone-melting
  • C30B13/16—Heating of the molten zone
  • C30B13/22—Heating of the molten zone by irradiation or electric discharge
• • 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
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/29—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials characterised by the substrates
  • H10P14/2901—Materials
  • H10P14/2922—Materials being non-crystalline insulating materials, e.g. glass or polymers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/34—Deposited materials, e.g. layers
  • H10P14/3402—Deposited materials, e.g. layers characterised by the chemical composition
  • H10P14/3404—Deposited materials, e.g. layers characterised by the chemical composition being Group IVA materials
  • H10P14/3411—Silicon, silicon germanium or germanium
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P14/00—Formation of materials, e.g. in the shape of layers or pillars
  • H10P14/20—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials
  • H10P14/38—Formation of materials, e.g. in the shape of layers or pillars of semiconductor materials characterised by treatments done after the formation of the materials
  • H10P14/3802—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
  • H10P14/382—Scanning of a beam
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P34/00—Irradiation with electromagnetic or particle radiation of wafers, substrates or parts of devices
  • H10P34/40—Irradiation with electromagnetic or particle radiation of wafers, substrates or parts of devices with high-energy radiation
  • H10P34/42—Irradiation with electromagnetic or particle radiation of wafers, substrates or parts of devices with high-energy radiation with electromagnetic radiation, e.g. laser annealing

Definitions

• the invention relates to a method for the crystallization of thin semiconductor layers on a substrate material, in particular for the targeted crystallization of silicon films without the need for germs by means of laser radiation in so-called SOI structures (SOI: silicon insulator / silicon on insulation). gate), as well as a device for carrying out this method.
• SOI structures silicon insulator / silicon on insulation. gate
• SOI structures are of technical importance for a number of electronic components, in particular in integrated circuits (hereinafter referred to as "IC").
• IC integrated circuits
• a cross section through a substrate material with an SOI structure is shown schematically in the attached FIG. 1.
• an insulator layer I here for example a 0.5 ⁇ m thick SiO 2 layer, is on a silicon base layer (bulk Si), and a polycrystalline silicon layer, here for example also 0.5 ⁇ m thick, is on this insulator layer I.
• Surface layer S is formed.
• SOI-IC integrated circuits
• three-dimensional ICs in particular can also be produced if IC substrates which are provided with a suitable insulator layer are used as substrates for the Si layer to be crystallized.
• SOI technology The formation of three-dimensional IC structures using SOI technology is described in the articles by Y. Akasaka et al. "Trends In Three-Dimensional Integration” (Solid State Technology, February 1988, pp. 81 to 89) and "Three-Dimensional IC Trends (Proc. Of the I ⁇ E, vol. 74, No. 12, Dec. 86, p. 1703-1714).
• the object of the present invention is to provide a process with which a targeted crystallization of thin semiconductor layers, in particular of single-crystalline silicon films on an SOI structure, can take place by producing a melt with a predetermined temperature
• a growth nucleus is reproducibly selected in a semiconductor surface layer solely by means of the radiated energy, and a stable single-crystal layer growth is subsequently achieved.
• a device is also to be specified with which this method can be carried out.
• the surface layer of a semiconductor structure is then melted locally, a temperature profile being generated in the melt which has a "supercooled" area running symmetrically to the center, the lateral dimensions of which are of the same order of magnitude as the thickness of the melt .
• An SOI structure is used in particular as the semiconductor substrate material, so that the melt is produced in the polycrystalline silicon surface layer, from which the crystallization of a single-crystalline silicon layer then takes place.
• energy is preferably irradiated onto the substrate by means of a laser which is operated in a TEM n - or TEM "- * vibration mode.
• TEM nn modes can also be used to generate the required temperature profile of a laser, which are superimposed so that an intensity profile comparable to the TEM - ⁇ mode results.
• the intensity profiles of a laser beam in the EM n1 oscillation mode or when two TEM Q modes are superimposed are shown in FIG.
• An essential feature of the intensity distribution that arises is that two intensity maxima occur symmetrically to a central intensity minimum.
• the temperature profile in the melt that follows the intensity profile of the laser beam in a targeted manner, ie to specify the lateral dimensions of the “supercooled” area of the melt as a function of the distance a intensity minimum - intensity maximum.
• the intensity distribution of the laser beam is selected such that the supercooled region of the melt which is formed symmetrically to the beam scanning direction is comparable in its lateral dimensions to the thickness of the melt. This results in an "automatic" seed selection with subsequent stable single-crystal layer growth. If the surface layer of the semiconductor substrate is made of silicon, the crystallized layer shows a (100) orientation, the layer growth taking place in a ⁇ 100> direction which is identical to the scanning or scanning direction.
• the lateral extent of the area of critical subcooling in the melt should be three to five times the layer thickness.
• the scanning speed of the intensity-modulated laser beam is preferably 10 to 500 mm / sec, the beam diameter (at 1 / e intensity) on the substrate surface
• the crystallization can take place in a chamber filled with doping gas, so that the crystallized layer can be specifically doped during the growth process.
• doping silicon preference is given to using phosphine (PH.) Or arsine (AsH to produce n-type layers, diborane (B_H g ) or boron trichloride (BC1_.) To produce p-type layers.
• single-crystalline semiconductor layers on a substrate material can be crystallized in a targeted manner - also computer-controlled - in any direction and without doping, without an additional covering layer to stabilize the substrate provide molten surface.
• This is particularly interesting for reasons of economy, if one takes into account that only a small part of the surface of an IC chip (about 15%) is covered with active components and must therefore be single-crystal.
• FIG. 1 shows a schematic cross section through an SOI structure (S_ilicon-on-insulator);
• FIG. 2 intensity profiles of a laser beam in TEM n - oscillation mode and when two TEM __ oscillation modes are superimposed;
• FIG. 3 shows the schematic structure of a device with an Ar laser for selective crystallization according to the method according to the invention.
• FIGS. 4a and 4b scanning electron microscope images of recrystallized polysilicon regions on an SOI structure, which were achieved with laser beams in the TEM vibration mode (a) or in the TEM vibration mode (b).
• FIG. 1 The structure of a device for carrying out the method according to the invention is shown schematically in FIG. According to this arrangement, a prism 1, a laser tube 2 for generating the laser beam (here an Ar laser), an adjustable aperture diaphragm 3, a coupling-out mirror 4, an electro-optical modulation device with an ADP crystal 5 are arranged one behind the other in the beam path of a laser beam and a dielectric polarizer 6, a ⁇ / 4 plate 7, an objective 8 and the wafer 9 to be irradiated.
• a prism 1 a laser tube 2 for generating the laser beam (here an Ar laser), an adjustable aperture diaphragm 3, a coupling-out mirror 4, an electro-optical modulation device with an ADP crystal 5 are arranged one behind the other in the beam path of a laser beam and a dielectric polarizer 6, a ⁇ / 4 plate 7, an objective 8 and the wafer 9 to be irradiated.
• a prism 1 a laser tube 2 for
• Vibration modes or the TEM nn vibration modes of the laser posed.
• TEM oscillation modes are selected, they are superimposed in such a way that an intensity profile of the laser beam comparable to the TEM n mode results.
• the ⁇ j4 plate 7 is arranged in the beam path in order to maintain a constant, i.e. to achieve non-oscillating absorption of the laser radiation in the melted or to be melted material layer.
• the portion of the beam reflected from the surface of the wafer 9 is suppressed by the ⁇ / 4 plate 7, since this reflected, circularly polarized portion of the beam is linearly polarized again as it passes through the ⁇ / 4 plate 7, but the direction of polarization is perpendicular to the direction of polarization of the incident laser beam.
• the reflected beam portion can therefore not pass the dielectric polarizer 6 and therefore does not get back into the laser resonator.
• the desired beam diameter on the surface of the wafer 9 is set via the focal length of the lens 8.
• the beam movement on the substrate 9 can take place, for example, by means of mechanically moved mirrors or electro-optical deflection elements or also by the mechanical adjustment of an x-y table on which the wafer 9 is arranged. These elements for deflecting the beam on the substrate surface are not shown in FIG. 3.
• the control of the beam movement or the control of the x-y table and the modulation of the light intensity is carried out by a computer.
• FIG. 4 shows a selectively crystallized Si layer after structural etching has taken place, as has been achieved by the method according to the invention with the device explained above with reference to FIG. 3.
• the substrate surface was scanned from top to bottom with a laser beam using a TEM.
• Profile in the structure according to FIG. 4b, scanned from bottom to top with a laser beam with a TEM Q1 profile.
• the 1 / e diameter in the laser focus was 10 ⁇ m with a laser line of 2 watts and a light wavelength of 488 nm.
• a 0.5 ⁇ m thick polycrystalline Si layer was crystallized, which by means of chemical layer deposition (CVD) on an amorphous SiO ? -Sub ⁇ trat had been produced.
• CVD chemical layer deposition

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Recrystallisation Techniques (AREA)
• Liquid Deposition Of Substances Of Which Semiconductor Devices Are Composed (AREA)

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• 1988
  • 1988-05-31 DE DE3818504A patent/DE3818504A1/de active Granted
• 1989
  • 1989-05-30 WO PCT/DE1989/000342 patent/WO1989012317A1/de not_active Ceased
  • 1989-05-30 DE DE89DE8900342A patent/DE3990622D2/de not_active Expired - Lifetime

Patent Citations (1)

Non-Patent Citations (7)

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