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
  • H10F77/00—Constructional details of devices covered by this subclass
  • H10F77/10—Semiconductor bodies
  • H10F77/14—Shape of semiconductor bodies; Shapes, relative sizes or dispositions of semiconductor regions within semiconductor bodies
  • H10F77/148—Shapes of potential barriers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/813—Bodies having a plurality of light-emitting regions, e.g. multi-junction LEDs or light-emitting devices having photoluminescent regions within the bodies
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10D—INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
  • H10D8/00—Diodes
• • 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
  • H10F30/21—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 the devices being sensitive to infrared, visible or ultraviolet radiation
  • H10F30/22—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 the devices being sensitive to infrared, visible or ultraviolet radiation the devices having only one potential barrier, e.g. photodiodes
  • H10F30/223—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 the devices being sensitive to infrared, visible or ultraviolet radiation the devices having only one potential barrier, e.g. photodiodes the potential barrier being a PIN barrier
• • 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
  • H10F39/12—Image sensors
• • 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
  • H10F71/00—Manufacture or treatment of devices covered by this subclass
  • H10F71/127—The active layers comprising only Group III-V materials, e.g. GaAs or InP
  • H10F71/1272—The active layers comprising only Group III-V materials, e.g. GaAs or InP comprising at least three elements, e.g. GaAlAs or InGaAsP
• • 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
  • H10F77/10—Semiconductor bodies
  • H10F77/14—Shape of semiconductor bodies; Shapes, relative sizes or dispositions of semiconductor regions within semiconductor bodies
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/81—Bodies
  • H10H20/811—Bodies having quantum effect structures or superlattices, e.g. tunnel junctions
  • H10H20/812—Bodies having quantum effect structures or superlattices, e.g. tunnel junctions within the light-emitting regions, e.g. having quantum confinement structures
• • 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
  • H10F77/30—Coatings
  • H10F77/306—Coatings for devices having potential barriers
  • H10F77/331—Coatings for devices having potential barriers for filtering or shielding light, e.g. multicolour filters for photodetectors
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy
  • Y02E10/544—Solar cells from Group III-V materials
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• the present application relates to a radiation receiver and a method for producing a radiation receiver.
• the radiation receiver comprises a semiconductor body having a first active region and a second active region.
• the first active Area and the second active area are each provided for the detection of radiation.
• the first active region and the second active region are spaced apart in the vertical direction.
• a tunnel area is arranged between the first active area and the second active area.
• the tunnel region is electrically conductively connected to a connection surface, which is provided for external electrical contacting of the semiconductor body between the first active region and the second active region.
• the semiconductor body therefore provides two active regions in which, in each case, a signal can be generated during operation of the radiation receiver, for example by generation and subsequent separation of electron-hole pairs upon impingement of electromagnetic radiation.
• a signal can be generated during operation of the radiation receiver, for example by generation and subsequent separation of electron-hole pairs upon impingement of electromagnetic radiation.
• the connection surface By means of the connection surface, the signals between the active areas can be tapped externally.
• the pad can be electrically conductively connected to the first active region and to the second active region.
• the pad can thus represent a common pad for the first active area and for the second active area. Between the active areas can thus be dispensed with separate pads for the active areas.
• the manufacture of the radiation receiver is thus simplified, resulting in reduced manufacturing costs and a lower risk of incorrect processing.
• the radiation receiver may also have more than two active regions, which may be formed in particular monolithically integrated into the semiconductor body.
• the semiconductor body may have a third active region on the side of the second active region facing away from the first active region. Between the second active region and the third active region, a further tunnel region can be arranged.
• the further tunnel region can be electrically conductively connected to a further connection surface.
• a tunnel region can be arranged between each two adjacent active regions, which can furthermore each be electrically conductively connected to a connection surface.
• the semiconductor body is externally electrically contactable between each two adjacent active regions.
• the tunnel region and / or the further tunnel region can each have at least two tunnel layers with mutually different conductivity types.
• a tunnel layer of the tunnel region or of the further tunnel region may be n-doped and a further tunnel layer of the tunnel region or of the further tunnel region may be doped p-doped.
• the tunnel layers can each be highly doped and, in particular, have a doping concentration of at least 1 ⁇ 10 19 cm -3 , proceeding from at least 1 ⁇ 10 20 cm -3 .
• the production of an electrically conductive connection with the connection surface or further connection surface arranged outside the semiconductor body is thus simplified.
• the tunnel surface of the tunnel region facing the connection surface may have the same conductivity type as the tunnel layer of the further tunnel region facing the further connection surface.
• the connection surface and the further connection surface may be of a similar design, in particular with regard to a low contact resistance to the semiconductor body.
• connection area and the further connection area can be produced in a common deposition step.
• the manufacturing process is simplified.
• At least one of the active regions may be arranged between a barrier layer and a counter-barrier layer.
• the active regions may each be arranged between an associated barrier layer and an associated counter-barrier layer.
• the barrier layer and the counter-barrier layer may each have different types of lines from each other.
• the active region can be embodied in each case undoped or intrinsically doped.
• a pin diode structure can be realized in this way.
• the barrier layers may have the same conductivity type and may be upstream of the associated active regions.
• the radiation receiver can have a structure of stacked diodes, wherein the polarity of the diodes is identical with respect to a main direction of radiation.
• the semiconductor body may have a main radiation input surface. Through this main radiation inlet surface can a large part of the radiation to be detected in the active regions can be coupled into the semiconductor body.
• the main radiation inlet surface of the semiconductor body may bound the semiconductor body in a vertical direction, that is, in a direction perpendicular to a main extension plane of the semiconductor layers of the semiconductor body.
• the main radiation inlet surface of the semiconductor body may further be formed stepwise.
• the main radiation inlet surface can thus have a plurality of step surfaces.
• a step surface is understood as an area extending in a lateral direction, that is to say in a main extension plane of the semiconductor layers of the semiconductor body.
• a step surface in the lateral direction may be delimited by at least one side surface which is inclined or perpendicular to the main extension plane.
• each active region can be assigned a step surface.
• the radiation to be detected in the respective active region can therefore be coupled into the semiconductor body predominantly through the respectively assigned step surface.
• the radiation to be respectively detected in the active regions can thus strike the respective active region without having previously passed through one of the upstream active regions.
• the radiation to be received in the respective active region predominantly radiates into the active surface through the step surface of the main radiation inlet surface assigned to this active region Area.
• the active areas can thus be designed largely independently of the other, these upstream active areas.
• the ratios of the signals generated in the active regions to one another can be set largely independently of the base area of the active regions via the relative surface portions of the associated step surfaces.
• two active areas with mutually different base areas can generate signals of comparable height.
• a main radiation entrance surface of a semiconductor body is not designed as step-shaped, if it has recesses provided only for contacting buried semiconductor layers and only a small proportion of radiation, approximately 10% or less, in the region of the depressions compared with the total main radiation surface Semiconductor body is coupled.
• a step surface can be formed in each case between two adjacent active regions.
• the assignment of the step surfaces to the associated active areas is thus simplified.
• the tunnel region can be removed at least in regions. Absorption of the radiation to be detected in the active region downstream of the tunnel region can be avoided in the region of the step surface.
• at least two step surfaces are arranged in plan view next to each other.
• the step surfaces may be formed so that a connecting line between any two points of a step surface in supervision does not pass through another step surface.
• the step surfaces may each have a polygonal, approximately triangular or quadrangular, basic shape.
• the step surfaces can be designed in their shape so that the step surfaces have a minimum possible total length of the borders for a given area. The risk that leakage currents occurring along the border may affect the sensitivity of the radiation receiver can thus be minimized.
• At least two step surfaces engage in a plan view of the semiconductor body in some areas.
• one of the step surfaces may be comb-like, with at least some other step surface extending in the intermediate spaces.
• the step surfaces can be distributed comparatively homogeneously over the base surface of the radiation receiver. So are also in spatially inhomogeneous irradiation of the
• Radiation receiver the spectral components of the incident radiation and in particular their relationship to each other reliably determined.
• the first active area may be upstream of the second active area.
• upstream refers in each case to the relative arrangement along a main direction of the radiation incidence, in which case the term “upstream”, with reference to the incident radiation, however, does not require that radiation impinging on an element of the radiation receiver must first pass through an element arranged upstream of this element.
• radiation impinging on the second active region can pass through the step surface associated with this active region without passing through the upstream first active region.
• the step surface assigned to the first active region can furthermore be designed to be continuous. An external electrical contact of the first active region is so simplified.
• the step surface assigned to the second active region can at least partially circulate the step surface assigned to the first active region.
• An area formed by means of the step area assigned to the first active area and the step area assigned to the second active area can thus be formed in a simplified, connected manner. An external electrical contacting of the second active region, in particular by means of the connection surface, is thereby simplified.
• the formation of a step surface can also be dispensed with.
• the radiation can pass through a common, in particular non-segmented, main radiation inlet surface for all active regions. Before the radiation hits an active area, it passes through the other one in this case or the other active areas that precede this active area.
• the active regions may be sensitive in the visible spectral range.
• the active regions can each have a detection maximum at a peak wavelength, wherein at least one peak wavelength lies in the visible spectral range.
• the peak wavelengths may be spaced apart.
• the radiation receiver can have three active regions which have a peak wavelength in the red, green and blue spectral range.
• a color sensor By means of such a radiation receiver, a color sensor can be realized in a simple manner, which in each case generates a signal for the three primary colors red, green and blue.
• the radiation of a full-color display device can be monitored.
• the color sensor can be provided in particular for adaptation of the relative intensities of the radiated radiation to a predetermined value, in particular for white balance.
• At least one of the radiation receivers can be made spectrally narrow-band. The less the overlapping of the spectral detection areas of the active areas, the better the separation of separate color signals.
• a distance between the peak wavelengths of two adjacent detection maxima may be greater than the sum of the half-value widths respectively associated with these detection maxima.
• HWHM half spectral width at half the maximum value
• the peak wavelengths may increase along the main direction of the radiation entrance.
• the active regions may have peak wavelengths in the blue, green, and red spectral regions.
• At least one active region along the main direction of the radiation incidence may have a smaller peak wavelength than an upstream active region.
• the upstream active region can therefore be designed to be absorbent for the radiation having the shorter peak wavelength.
• the radiation to be received in the downstream active region can be coupled in through the step surface assigned to this active region.
• the order of the active regions in the vertical direction can thus be chosen independently of their peak wavelength. In the deposition of the semiconductor body, the order of the active regions can therefore be optimized with regard to other criteria, for example the lattice parameters of the semiconductor materials used in each case for the active regions.
• At least one of the active regions may be preceded by a passive region.
• the passive region may be provided for forming a short-wave edge of a spectral detection region of the associated active region.
• a passive region is understood to be a region in which radiation absorbed therein has no or at least no significant contribution to the signal of the associated active area.
• a passive region can be formed, for example, by means of a doped semiconductor layer, but electron-hole pairs generated during the radiation emergence are not separated from one another and subsequently recombined again.
• the passive region may comprise a semiconductor layer whose bandgap is greater than a bandgap of a semiconductor layer of the associated active region.
• the short-wave edge of the detection region of the active region can be easily formed. A spectral overlap between two detection areas can thus be reduced.
• At least one of the active regions may include a III-V compound semiconductor material.
• III-V compound semiconductor materials can have a high absorption efficiency.
• a material based on phosphide compound semiconductors is suitable for detection in the visible spectral range.
• a semiconductor layer comprises a phosphorus-containing compound semiconductor, in particular Al n Ga m Ini_ nm P, where 0 ⁇ n ⁇ 1, 0 ⁇ m ⁇ 1 and n + m ⁇ 1 can also apply to n ⁇ 0 and / or m ⁇ 0.
• This material does not necessarily have to have a mathematically exact composition according to the above formula, but rather it can have one or more dopants and additional constituents that have the physical properties essentially not change the material.
• the above formula includes only the essential constituents of the crystal lattice (Al, Ga, In, P), even though these may be partially replaced by small amounts of other substances.
• An active region based on phosphide compound semiconductors may be distinguished by a high absorption efficiency in the visible spectral range, while at the same time the sensitivity in the infrared spectral range may be low. Additional, external filters for blocking infrared radiation can thus be dispensed with.
• the radiation receiver can therefore be made particularly compact.
• the active areas may be different from each other in material composition.
• the active regions may have different bandgaps from each other.
• Such active regions intrinsically show a different absorption behavior from each other.
• a spectrally broadband radiation receiver such as a silicon detector, therefore, can be dispensed with separate filter layers for the selection of individual spectral ranges.
• the radiation receiver can be provided in particular for operation in a color sensor.
• a color sensor is generally understood to mean a sensor which in each case is a signal for at least two spectral ranges which are different from one another supplies. The spectral ranges do not necessarily have to be in the visible spectral range.
• the color sensor may have a plurality of color channels, such as three color channels or more.
• the tapped off at the pads of the radiation receiver signal can be supplied to an evaluation circuit of the color sensor.
• an active region of the radiation receiver is individually contacted for each color channel.
• the signals of the active regions can be tapped independently of one another, for example in parallel or in succession.
• the active regions of the radiation receiver can be contacted with respect to a common connection surface as a reference contact, for example with respect to an upper connection surface or a lower connection surface.
• the active regions can be interconnected in series by means of the tunnel regions.
• the signals for the individual color channels can be generated in particular by means of an arithmetic operation, for example a subtraction, from the signals which can be tapped off at the connection surfaces.
• a semiconductor body is provided.
• the semiconductor body has a first active region and a second active region, wherein the active regions are respectively provided for the detection of radiation, and wherein a tunnel region is arranged between the first active region and the second active region.
• the tunnel area becomes exposed, the first active area is removed area by area.
• On the exposed tunnel area a connection surface is formed.
• the radiation receiver is completed. The process steps need not necessarily be performed in the order given.
• a semiconductor body can be produced in a simplified manner, which can be contacted via the connection area between the first active area and the second active area.
• the semiconductor body can be epitaxially deposited on a growth substrate, for example by means of MOCVD or MBE. During production, the growth substrate may be thinned or removed. This can be done over the whole area or at least in certain areas.
• the exposure of the tunnel region can be carried out by means of wet-chemical etching.
• the tunnel area can serve as an etch stop.
• the exposure can be carried out by means of material-selective wet-chemical etching.
• the tunnel region is in particular formed by means of a material group which is different in respect of the etching behavior from the material used for the active regions.
• the tunnel region and the active regions may be based on materials containing different group V materials from each other.
• at least one of the active regions, in particular all active regions can be based on a phosphide compound semiconductor material.
• the tunnel area and possibly further tunnel areas may be based on an arsenide compound semiconductor material.
• a semiconductor layer based on arsenide compound semiconductors contains an arsenic-containing compound semiconductor, in particular of the material system Al n Ga m Ini- nm As, where O ⁇ n ⁇ l, O ⁇ m ⁇ l and n + m ⁇ 1.
• n ⁇ 0 and / or m ⁇ 0 apply.
• This material does not necessarily have to have a mathematically exact composition according to the above formula. Rather, it may include one or more dopants as well as additional ingredients that do not substantially alter the physical properties of the material.
• the above formula contains only the essential components of the crystal lattice (Al, Ga, In, As), even though these may be partially replaced by small amounts of other substances.
• the semiconductor body may have a third active region on the side of the second active region which faces away from the first active region. Between the second active region and the third active region, a further tunnel region can be arranged. On the tunnel area and the further tunnel area, in each case one connection area can be deposited in a common deposition step. The preparation of the radiation receiver is simplified.
• connection surface arranged outside the semiconductor body can take place, for example, by means of sputtering or vapor deposition.
• the method described is particularly suitable for producing a radiation receiver described above. Therefore, features described in connection with the method can also be used for the radiation receiver and vice versa. Further features, embodiments and expediencies will become apparent from the following description of the embodiments in conjunction with the figures.
• FIG. 1 shows a first embodiment of a radiation receiver in a schematic sectional view
• FIG. 2 shows the responsivities of the active regions in each case as a function of the wavelength of the incident radiation for a radiation receiver according to the first exemplary embodiment
• Figure 3 shows a second embodiment of a
• FIG. 4A and 4B a third embodiment of a radiation receiver in a schematic plan view (Figure 4A) and associated schematic sectional view (Figure 4B), ie Figures 5A and 5B, a first and second
• FIG. 1 shows a first exemplary embodiment of a radiation receiver 1 which has a semiconductor body 2.
• the semiconductor body 2 comprises a first active region 210, a second active region 220 and a third active region 230.
• the third active region is arranged on the side of the second active region which faces away from the first active region.
• the active areas When viewed on the semiconductor body, the active areas partially overlap.
• the first active region 210 covers the second active region 220 only in regions.
• the second active region 220 covers the third active region 230 only in regions.
• the first active area 210 is arranged upstream of the second active area 220. Furthermore, the second active region 220 is arranged upstream of the third active region 230 along this direction. Between two adjacent active regions, ie between the first active region 210 and the second active region 220 and between the second active region 220 and the third active region 230, a tunnel region 24 or a further tunnel region 25 is arranged.
• the tunnel region 24 projects beyond the active region 210 in the lateral direction at least in regions.
• a connection surface 31 or a further connection surface 32 is arranged on the tunnel region 24 and the further tunnel region 25 .
• the connection area and the further connection area are provided for the external electrical contacting of the semiconductor body 2 between the respective active areas, between which the tunnel areas are arranged.
• the pads are suitably made electrically conductive and may contain a metal, such as Au, Ti, Ni, Pt, Ag, Rh or Al, or a metallic alloy, in particular with at least one of said metals, or of such a metal or such a metallic Alloy exist.
• a metal such as Au, Ti, Ni, Pt, Ag, Rh or Al
• a metallic alloy in particular with at least one of said metals, or of such a metal or such a metallic Alloy exist.
• connection surfaces can also be designed as a multilayer.
• each active region has in each case a connection surface on both sides, as a result of which a signal generated in the active region during operation of the radiation receiver 1 is transmitted from the outside accessible from both sides of the active area.
• the semiconductor body 2 has a
• Main radiation entrance surface 10 which is formed stepwise. Each active region is assigned a step surface, via which the radiation to be received in the respective active region is coupled into the semiconductor body 2.
• the step surfaces each extend in the lateral direction and parallel to each other.
• the first active region 210 is assigned a first step surface 11, the second active region 220 a second step surface 12, and the third active region 230 a third step surface 13.
• the step surfaces are each offset from each other.
• the step surfaces run without overlap.
• a step surface is formed in each case.
• the radiation to be received in the third active region 230 can be coupled in via the step surface 13 and thus does not have to pass through the upstream active regions 210 and 220.
• the active regions of the semiconductor body 2 can thus be largely independently adapted to a spectral sensitivity characteristic predetermined for each active region.
• the spectral sensitivity of the active regions is thus independent or at least largely independent of optionally further active areas upstream of the respective active area.
• the sensitivities of the individual active regions 210, 220, 230 can be matched to one another and, in particular, adapted to each other via the area fraction of the respective step surfaces 11, 12, 13 on the entire main radiation inlet surface 10.
• the active regions 210, 220, 230 are each arranged between a barrier layer 211, 221, 231 and a counter-barrier layer 212, 222, 232, wherein the barrier layers are respectively arranged upstream of the assigned active regions.
• the active regions 210, 220, 230 may be intrinsic or undoped. Electron-hole pairs generated in the active regions can thus be separated from one another and can reach the respective connection surfaces 30, 31, 32, 33 via the respective barrier layers or counter-barrier layers.
• the barrier layers are each p-type and the counter-barrier layers are each n-type doped.
• the radiation receiver can thus be designed in accordance with stacked, monolithically integrated, pin diodes, wherein each diode is externally electrically contactable via the connection surfaces on both sides of the active region.
• the tunnel region 24 and the further tunnel region 25 each comprise a first tunnel layer 241 or a first further tunnel layer 251 and a second tunnel layer 242 or a second further one Tunnel layer 252, which have different types of lines from each other.
• the first tunnel layer 241 or 251 respectively has the same doping as the counter barrier layer 212 or 222 nearest to it and the second tunnel layer 242, 252 have the same doping as the barrier layer 221, 231 located closest thereto.
• Charge carriers can thus reach the connection surface 31 or the further connection surface 32 in a simplified manner from both sides of the tunnel region 24 or the further tunnel region 25.
• the signals of three active areas are accessible externally over a total of four connection surfaces.
• both charge carriers from the first region 210, in particular through the counter-barrier layer 212, and charge carriers from the second active region 220, in particular through the barrier 222 can reach the connection surface 31 via the tunnel region 24 and be tapped there.
• Between two active areas so separate pads for the barrier layer and for the counter-barrier layer are not required.
• Separate exposure of the barrier layer and the counter-barrier layer for example by means of two separate etching steps with different etching depths, can thus be dispensed with. In particular, this can reduce the number of etching steps required.
• both the number of connection surfaces and the number of etching steps can be reduced by the tunnel regions 24, 25.
• the production of the radiation receiver 1 This simplifies and thus reduces the risk of false production. Furthermore, the proportion of the surface of the radiation receiver, which is shadowed by pads, is reduced. The radiation can be coupled improved in the radiation receiver.
• the tunnel layers 241, 242, 251, 252 can each be highly doped, for example with a doping concentration of at least 1 ⁇ 10 19 cm -3 , in particular at least 1 ⁇ 10 20 cm -3 .
• the tunnel layers Due to the high doping, the tunnel layers have a comparatively high transverse conductivity.
• the tunnel region in particular the tunnel layers, facilitates the supply of the charge carriers released in the active regions by the production of electron-hole pairs to the connection surface 31 or to the further connection surface 32.
• the currents occurring can be in the range of a few microamps in particular.
• Additional contact finger structures formed outside the semiconductor body 2 can thus be dispensed with.
• the preparation of the radiation receiver is simplified.
• contact finger structures may additionally be provided.
• the first tunnel layer 241 of the tunnel region 24 and the first tunnel layer 251 of the further tunnel region 25 have the same conductivity type.
• An ohmic connection to the respective connection surfaces 31 and 32 can thus be achieved with identically designed connection surfaces.
• the external electrical contacting of the semiconductor body 2 between the active regions is thus simplified.
• the active regions 210, 220, 230 are each preceded by a passive region, that is to say a first passive region 213, a second passive region 223 or a third passive region 233.
• the passive regions 213, 223, 233 each have the same doping as the barrier layer 211, 221 or 231 adjacent thereto.
• absorption in the passive regions does not, or at least not significantly, produce a signal.
• the passive regions can thus each fulfill the function of a monolithically integrated filter layer in the semiconductor body.
• the spectral sensitivity can be set for the respectively assigned active region. A spectral separation of the detection areas of the active areas is simplified.
• Deviating from the illustrated embodiment can also be dispensed with the passive layers.
• semiconductor layers in particular the barrier layers, the counter barrier layers, the tunnel layers and the passive regions, may also be inverted with respect to their conductivity type, that is, the n-type doped semiconductor layers may be p-type doped and vice versa.
• the active regions can also be formed by means of a space charge zone, which can occur at a pn junction. A separate, intrinsically or undoped layer between the respective barrier layer and the associated counter-barrier layer is not required.
• the radiation receiver can also have only two active areas or more than three active areas.
• the coupling of the radiation into the active regions can take place predominantly via a common, in particular non-segmented, radiation entrance surface.
• the upstream active regions may be removed in only comparatively small regions in order to expose the respective tunnel regions and to provide connection surfaces on the exposed tunnel regions.
• Such a configuration is particularly expedient if the radiation provided for detection is absorbed only to a sufficiently small extent in the layers upstream of the respective active region, for example in an upstream, other active region or an upstream tunnel region.
• the semiconductor body 2 can be arranged deviating from the embodiment shown on a support.
• This carrier can be produced, for example, by means of a growth substrate for the semiconductor layers of the Semiconductor body 2 may be formed.
• the growth substrate may be removed in regions or removed or thinned in areas.
• the lower pad can be arranged on the side facing away from the semiconductor body 2 of the growth substrate.
• the described structure of the radiation receiver is particularly suitable for a color sensor, which generates a signal for mutually different spectral detection areas.
• the detection areas may be in particular in the ultraviolet, in the visible or in the infrared spectral range.
• the semiconductor body 2 in particular the active regions 210, 220, 230, may be based on a III-V compound semiconductor material.
• a Farbtripeis such as in the red, green and blue spectral range
• active areas are particularly active areas based on a phosphidic compound semiconductor material, in particular Al n Ga 1n In 1-nm P, where 0 ⁇ n ⁇ 1, O ⁇ m ⁇ l and n + m ⁇ 1.
• a phosphidic compound semiconductor material in particular Al n Ga 1n In 1-nm P, where 0 ⁇ n ⁇ 1, O ⁇ m ⁇ l and n + m ⁇ 1.
• FIG. 1 An example of the spectral sensitivity of a radiation receiver, which is embodied as described in connection with FIG. 1, is shown in FIG.
• the curves 621, 622 and 623 each show the Re ⁇ pons Kunststoff a detector in the blue, green or red spectral range as a function of the vacuum wavelength ⁇ of the radiation incident on the radiation receiver.
• curve 620 shows the spectral sensitivity distribution of the human eye (V ⁇ curve).
• the first active region provided for the detection of blue radiation is based on AlInP.
• the first active region 210 is assigned a passive region 213 based on GaP.
• the peak wavelength of the first active region is about 470 nm.
• the peak wavelength of the second active region is about 530 nm.
• the third active region 230 provided for the detection of red radiation is based on GaInP.
• the peak wavelength of the third active region is about 640 nm.
• the passive regions each have a bandgap greater than the bandgap of the active region to which they are associated.
• the short-wave edge of the respective reflectivity spectrum can thus be adjusted in a targeted manner by absorption of the shorter-wave radiation in the associated passive range.
• FIG. 2 shows that the spectral detection regions of the active regions 210, 220, 230 have only a comparatively slight overlap.
• the spectral detection ranges are each designed in such a narrow band that the spectral distance between two adjacent peak wavelengths is greater than the sum of the half-widths of the half-widths assigned to these detection ranges.
• the peak wavelengths of the active regions need not necessarily increase along the main direction of the radiation entrance. Rather, at least one active region may be preceded by another active region having a larger peak wavelength.
• the material composition of all or at least some phosphidic semiconductor layers can be chosen such that they are lattice-matched or at least largely lattice-matched to the arsenide tunnel regions.
• the phosphidic semiconductor layers may have an indium content of about 50%.
• FIG. 3 shows a second embodiment of a radiation receiver 1 is shown in a schematic plan view. In the vertical direction, the radiation receiver can be designed as described in connection with FIG.
• the main radiation inlet surface 10 is formed in steps and has a first step surface 11, a second step surface 12 and a third step surface 13. By Through the step surfaces, the radiation can be coupled into the active regions associated with the respective step surfaces.
• the step surfaces are arranged flat next to each other. A connecting line between any two points of a step surface does not pass through another step surface.
• the step surfaces may also have other comparatively simple geometric basic shapes, in particular polygonal, approximately triangular or quadrangular basic shapes.
• the step surfaces may be shaped such that the sum of the boundary lines between the step surfaces is minimized. The risk of leakage occurring at the interfaces and a concomitant reduced sensitivity of the radiation receiver can be minimized as much.
• FIGS. 4A and 4B A third exemplary embodiment of a radiation receiver is shown in FIGS. 4A and 4B in a schematic plan view and associated sectional view along the line AA '.
• the layer structure of the semiconductor body 2 can be designed as described in connection with FIGS. 1 and 2.
• the passive regions are not shown in the sectional view shown in FIG. 4B. However, these can, as described in connection with Figures 1 and 2, provided and executed.
• the step surfaces are arranged in this embodiment, that the step surfaces with an increased uniformity over the Main radiation entrance surface 10 are distributed.
• a reliable signal can thus be generated in a simplified manner.
• the improved spatially homogeneous sensitivity distribution can be achieved without significantly increasing the manufacturing outlay compared to the exemplary embodiment described in connection with FIG.
• the first step area 11 associated with the first active area 210 is designed to be continuous. Thus, the signal generated in the first active region can be tapped in a simplified manner via the upper connection surface 30.
• the second step surface 12 assigned to the second active region 220 runs around the first step surface 11 in the inner region of the main radiation inlet surface 10.
• the second step surface adjoins the first step surface.
• the surface formed jointly by the first step surface and the second step surface is thus contiguous.
• An external contact of the radiation receiver by means of the first connection surface 31 is simplified. Furthermore, this results in the production of the radiation receiver increased manufacturing tolerances in forming the step surfaces.
• the third step surface 13 associated with the third active region 230 engages, at least in some areas, in the first step surface 11 assigned to the first active region.
• the third step surface 13 need not be contiguous. Rather, these island-like portions may have, as the further tunnel layer 25 also in the production of island-like areas of the third step surface 13 does not have to be severed.
• a spatially homogeneous distributed over the main radiation entrance surface 10 sensitivity of the active regions 210, 220, 230 is simplified.
• the step surfaces may be formed strip-shaped at least partially.
• at least one step surface, approximately as shown in the exemplary embodiment, the first step surface 11 may be formed like a comb.
• the strips may have a width between about 8 ⁇ m and 100 ⁇ m, in particular between 8 ⁇ m and 50 ⁇ m inclusive.
• a center distance between two adjacent strips of a step surface may in this case be for example twice the strip width.
• the minimum strip width is dependent, in particular, on manufacturing tolerances, such as the adjustment tolerance for different photolithographic steps and the undercuts occurring in wet-chemical production processes.
• FIG. 5 shows a first exemplary embodiment of a color sensor 5.
• the color sensor has a radiation receiver 1, which can be embodied in particular as described in connection with FIGS. 1 to 4B.
• the color sensor has an evaluation circuit 4, which has a first evaluation unit 41, a second evaluation unit 42 and a third evaluation unit 43 includes.
• Each evaluation unit is connected to two connection surfaces, wherein the connection surfaces are each arranged on different sides of the respective active region and in each case represent the nearest connection surface on both sides of the active region.
• the first evaluation unit 41 is electrically conductively connected to the upper connection surface 30 and the connection surface 31.
• the active areas can each be operated by means of a bias or photovoltaic. The signals of the active areas can be tapped sequentially or in parallel.
• Each evaluation unit is intended to output a signal for each color channel.
• FIG. 5B A second exemplary embodiment of a color sensor is shown in FIG. 5B.
• the evaluation units 41, 42, 43 are electrically conductively connected to a common connection area as a reference contact.
• the common electrical connection surface is the upper connection surface 30.
• the active regions 210, 220, 230 are electrically connected to each other in series by means of the tunnel regions 24, 25. From the tapped on the pads signal can be generated by means of the evaluation, such as by means of an arithmetic operation such as a difference, the corresponding signal for each color channel.
• An exemplary embodiment of a production method of a radiation receiver is shown schematically in sectional view on the basis of the intermediate steps illustrated in FIGS. 6A to 6F.
• a semiconductor body 2 having a semiconductor layer sequence is provided.
• the semiconductor layer sequence of the semiconductor body can be deposited epitaxially on a growth substrate 20, for example by means of MBE or MOVPE.
• the semiconductor layer sequence can be embodied as described in connection with FIG.
• the method is shown for simplicity of illustration only for the manufacture of a single radiation receiver.
• a plurality of radiation receivers can be produced side by side and further separated subsequently.
• the singulation can be done, for example, mechanically, for example by means of sawing, cutting or breaking, or chemically, for example by wet-chemical or dry-chemical etching.
• a laser separation method can also be used.
• the tunnel region 24 arranged between the first active region 210 and the second active region 220 is exposed in regions. This is done by means of area-wise removal of material of the overlying semiconductor layers, in particular of the first active region 210.
• the removal of the material can be carried out in particular by wet chemical etching.
• the tunnel region 24 may be designed such that it serves as an etch stop.
• phosphidic Semiconductor materials and arsenidic semiconductor materials with respect to a wet chemical etching process have a high selectivity.
• hydrogen chloride (HCl) etching can effectively remove phosphidic semiconductor material and stop it on an arsenide material with high selectivity.
• connection surface can subsequently be deposited in each case. This can be done in a common deposition process. For this example, vapor deposition or sputtering is suitable. A multilayered design of the connection surfaces can also be provided. Furthermore, an upper pad 30 is deposited on the passive region 213 associated with the first active region 210. This can be done together with the pad 31 and the further pad 32 or performed in a separate deposition step.
• the tunnel region 24 and the further tunnel region 25 are removed in regions.
• the passive areas 223 and 233 associated with the respective active areas 220, 230 can be exposed.
• the tunnel regions can therefore be designed to be absorbent for the radiation to be detected in the underlying active regions.
• this region-specific removal of the tunnel regions can also be dispensed with.
• the growth substrate 20 is removed as shown in FIG. 6F.
• the lower pad 33 can be deposited.
• the deposition of the lower pad can be done as described in connection with the pads 30, 31, 32.
• the semiconductor body 2 can be provided with a protective layer at least in regions (not explicitly shown). This can in particular cover the exposed side surfaces of the semiconductor body.
• the protective layer may include, for example, an oxide such as silicon oxide or titanium oxide, a nitride such as silicon nitride, or an oxynitride such as silicon oxynitride.
• the growth substrate 20 can also remain at least partially in the radiation receiver.
• the growth substrate 20 may also be removed only in regions or may be thinned over the entire surface or in regions.
• the production steps can also be carried out deviating from the described order, as far as appropriate.

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• 2008
  • 2008-01-31 DE DE102008006987A patent/DE102008006987A1/de not_active Withdrawn
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