Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F30/00—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors
  • H10F30/20—Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors the devices having potential barriers, e.g. phototransistors
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F77/00—Constructional details of devices covered by this subclass
  • H10F77/40—Optical elements or arrangements
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F39/00—Integrated devices, or assemblies of multiple devices, comprising at least one element covered by group H10F30/00, e.g. radiation detectors comprising photodiode arrays
  • H10F39/10—Integrated devices
  • H10F39/103—Integrated devices the at least one element covered by H10F30/00 having potential barriers, e.g. integrated devices comprising photodiodes or phototransistors
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F99/00—Subject matter not provided for in other groups of this subclass

Definitions

• the present invention relates to an optoelectronic microelectronic arrangement according to the preamble of patent claim 1 and a method for its production according to patent claim 7.
• a silicon substrate 10 of one conduction type with weak doping for example of the p-conduction type, trench isolations 11, 12 are provided for isolation against electronic functional units, such as the above-mentioned MOS transistors, in which it can be so-called STI areas (shallow trench isolation) with silicon dioxide.
• STI areas shallow trench isolation
• a zone 13 of one conduction type, that is to say of the p-conduction type, and a zone 14 of the opposite conduction type, that is to say of the n-conduction type are provided, which in comparison to the doping concentration of the substrate 10 have a large doping concentration.
• weak doping used above for substrate doping therefore means a low doping concentration compared to the doping concentration of zones 13 and 14. Between zones 13 and 14 there is therefore a weakly doped zone 15, which are also referred to in practice as an intrinsic zone can. If, as usual, a low doping concentration is marked with a minus and a large doping concentration with a plus sign, the result is, for the types of conduction given above for the substrate 10 and the zones 13 and 14, an optoelectronically active diode part of the zone sequence p + zone 13-, p ⁇ - zone 15 - and n + zone 14 -.
• an optical waveguide 16 which can consist, for example, of silicon oxide nitride / silicon dioxide.
• a photodiode of the type explained above represents a lateral or planar diode.
• the area of the optoelectronically active diode part must be as large as possible when viewed in the direction of the material.
• planar photodiodes require a comparatively large chip area in an integrated system, as a result of which the integration density is impaired.
• MOS transistors with ever shorter channel lengths.
• the resulting chip area is then at least partially nullified by planar photodiodes. This is particularly economical
• DE 26 24 436 A1 shows a photodiode structure in which, in order to improve the coupling of light, a structure protruding from a substrate is formed in the form of a mesa. The light couples into the mesa with a vertical component, so that the degree of coupling is increased. The mesa is formed in an epitaxial layer.
• a comparable photodiode structure is shown in DE 39 20 219 C2.
• the present invention is based on the object of specifying a photodiode structure which saves chip area in relation to a predetermined light yield and which, moreover, has MOS-
• a process for preparing a elec tronic ⁇ microelectronic assembly according to the invention is subject matter of patent claim 7. Further developments of the inventive concept with regard to the arrangement are the subject of corresponding subclaims.
• FIG. 2A shows a first embodiment of a vertical photodiode in cross section
• FIG. 2B shows a part of a layout of the vertical photodiode according to FIG. 2A;
• FIG. 3 shows a second embodiment of a vertical photodiode in cross section
• FIG. 4 shows an embodiment of a vertical MOS field-effect transistor to explain the production possibilities of optoelectronic microelectronic arrangements with such transistors and vertical photodiodes.
• a region 21 of a conduction type is formed in a silicon substrate 20 by a trough.
• a region 21 of a conduction type preferably of the n-conduction type, is formed in a silicon substrate 20 by a trough.
• zones 24, 25 of one conduction type with a high doping concentration compared to the doping concentration of the well region 21 are provided in the substrate 20 within the trench insulation 22, 23. Starting from a well region 21 with an n-line type, these are then zones of the n + line type .
• a vertical photodiode Essential for the formation of a vertical photodiode is the formation of a mesa 26, which has been prepared from the substrate 20 and is perpendicular to it, and thus has the same conductivity type and the same doping concentration as the well region 21.
• a zone 27 is provided with a line type opposite to the conductivity type of the well region and a comparatively high doping concentration. Starting again from a well region 21 with an n-line type, it is then a zone 27 of the p + line type.
• the zones 24, 25 (this may be also a single coherent zone act) formed the zone of the mesa 26 below the zone 27 so ⁇ as the zone 27th So it is assumed that the trays ⁇ area 21 can be considered as intrinsic region, there is a pin diode structure.
• Zone 27 also use a silicide layer, which creates a Schottky diode structure.
• a barrier layer is thus formed by the zone or layer 27.
• the mesa 26 is surrounded by an optical waveguide 28 which, as stated above, can consist of silicon oxide nitride / silicon dioxide.
• This optical waveguide 28 is provided on the substrate 20, preferably on an optical coating layer 32, on an oxide.
• the coupling of light from the optical waveguide 28 into the optoelectronically active diode part in the area of the zone of the mesa 26 below the zone 27 is schematically indicated by an arrow 33.
• the photodiode structure is completed by electrical contacts 29 and 30 for zone 27 and zones 24 and 25, respectively.
• a passivation 31 shown in broken lines, is provided, which can be oxides and / or nitrides.
• Diode part Light is thus Kitkop over the vertical side wall of the mesa in the opto-electronically active diode part ⁇ pelt.
• the desired large light coupling into the optoelectronically active diode part is decoupled from undesired light coupling via the substrate.
• two highly doped zones 44, 45 of different conduction types are provided, which extend from the trough region 21 below the mesa 26 along its edge. If it is again assumed that the well region 21 is of the n-line type, the zone 44 is of the n + line type and the zone 45 is of the p + line type .
• the mesa 26 is preferably surrounded by a hatched optical waveguide 47. From this optical waveguide 47, light is likewise coupled in via the vertical side wall of the mesa 26, which is indicated by an arrow 52. This in turn results in the favorable effects already explained with reference to the exemplary embodiment according to FIGS. 2A and 2B.
• the photodiode according to FIG. 3 is completed by electrical contacts 48, 49 for the zones 44, 45 and passivations 51 shown in broken lines.
• Photodiodes according to the invention of the type explained above are advantageously suitable for integration in integrated circuits with vertical MOS field-effect transistors known per se.
• a transistor is shown schematically in FIG. 4. It also builds on a substrate 60 with a well region 61, which is of the p-type in the case of an n-channel MOS transistor. Isolation from other functional units in one integrated Circuitry is formed by trench isolations 62, 63 (STI areas).
• STI areas trench isolations 62, 63
• a coherent zone 64 with a conductivity type that is opposite to its conductivity type and a comparatively large doping concentration. If the tub area has a p-line type, zone 64 is of the n + line type .
• a zone 66 is provided in a mesa 65 on its side facing away from the tub area 61, which zone is of the n + type of tubing for the tub area 61, zone 64 and the mesa 65 in the above-mentioned line types.
• the transistor structure is completed by a spacer 67 made of polysilicon or amorphous silicon, which is insulated from the mesa substrate, contacts 68, 69 for the zones 64, 66 and passivations 70 shown in broken lines.
• the formation of vertical photodiodes according to the invention is particularly well suited for integration in a CMOS process.
• CMOS process When integrating optoelectronic microelectronic arrangements with MOS transistors and photodiodes in a vertical configuration, it becomes possible, for example, to reduce the number of metallization levels for electrical connections and connections if photodiodes work as receivers in optical transmission links on a chip.
• self-adjustment techniques e.g. a spacer technology, additionally increase the integration densities if spacer thicknesses below the lithographic minimum width are used.
• Drain regions of MOS transistors and doped zones of photodiodes can be produced by implantation techniques.
• Oxide coating layers for photodiodes such as layers 32 and 50 according to FIGS. 2A, 2B and FIG. 3, can optionally be applied separately.
• Optical fibers are made of a material with a suitable refractive index and structured using a mask. Finally, passivations are applied and processes such as contact hole etching, silicidation and metallization are carried out. Silicidization takes place if, instead of a doped zone 27 according to FIG. 2A, a silicide layer is used to form a Schottky diode.
• optoelectronic ⁇ specific materials are in addition to silicon and dacarochode in question.

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• Solid State Image Pick-Up Elements (AREA)

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Citations (1)

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• 1999
  • 1999-09-07 DE DE19942692A patent/DE19942692B4/de not_active Expired - Fee Related
• 2000
  • 2000-09-06 KR KR10-2002-7003057A patent/KR100443685B1/ko not_active Expired - Fee Related
  • 2000-09-06 JP JP2001522591A patent/JP3836026B2/ja not_active Expired - Fee Related
  • 2000-09-06 WO PCT/DE2000/003073 patent/WO2001018867A1/de not_active Ceased
• 2002
  • 2002-03-07 US US10/093,320 patent/US6553157B2/en not_active Expired - Lifetime

Patent Citations (1)

Non-Patent Citations (6)

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