Abstract: A back-illuminated type solid-state image pickup device (1041) includes read circuits (Tr1, Tr2) formed on one surface of a semiconductor substrate (1042) to read a signal from a photo-electric conversion element (PD) formed on the semiconductor substrate (1042), in which electric charges (e) generated in a photo-electric conversion region (1052c1) formed under at least one portion of the read circuits (Tr1, Tr2) are collected to an electric charge accumulation region (1052a) formed on one surface side of the semiconductor substrate (1042) of the photo-electric conversion element (PD) by electric field formed within the photo-electric conversion element (PD). Thus, the solid-state image pickup device and the camera are able to make the size of pixel become very small without lowering a saturation electric charge amount (Qs) and sensitivity.

Abstract: (Problems) To provide an integrated circuit having the wiring structure including pads with a small wiring area and capable of highly integrating elements, a solid image pickup element having the wiring structure, and an imaging device having the solid image pickup element.

Abstract: A semiconductor substrate has a first principal face and a second principal face opposite thereto. A pixel unit, an analog circuit and a digital circuit are formed in a first, second and third region of the semiconductor substrate. An interconnect is formed on each of the first and second principal faces of the second region. A plurality of penetrative electrodes is formed in the semiconductor substrate to penetrate the first and second principal faces. These penetrative electrodes are electrically connected with interconnects formed in the first and second principal faces of the second region. A guard ring is formed in the semiconductor substrate to penetrate the first and second principal faces, the guard ring is surrounding the penetrative electrodes.

Abstract: A backside illuminated imaging device performs imaging by illuminating light from a back side of a p substrate to generate electric charges in the substrate based on the light and reading out the electric charges from a front side of the substrate. The device includes n layers located in the substrate and on an identical plane near a front side surface of the substrate and accumulating the electric charges; n+ layers between the respective n layers and the front side of the substrate, the n+ layers having an exposed surface exposed on the front side surface of the substrate and functioning as overflow drains for discharging unnecessary electric charges accumulated in the n layers; p+ layers between the respective n+ layers and the n layers and functioning as overflow barriers of the overflow drains; and an electrode connected to the exposed surface of each of the n+ layers.

Abstract: Two charge quantities (Q1,Q2) are output from respective pixels P (m,n) of the back-illuminated distance measuring sensor 1 as signals d?(m,n) having the distance information. Since the respective pixels P (m,n) output signals d?(m,n) responsive to the distance to an object H as micro distance measuring sensors, a distance image of the object can be obtained as an aggregate of distance information to respective points on the object H if reflection light from the object H is imaged on the pickup area 1B. If carriers generated at a deep portion in the semiconductor in response to incidence of near-infrared light for projection are led in a potential well provided in the vicinity of the carrier-generated position opposed to the light incident surface side, high-speed and accurate distance measurement is enabled.

Abstract: A system for fabricating semiconductor components includes a semiconductor substrate, a thinning system for thinning the semiconductor substrate, an etching system for forming the substrate opening, and a bonding system for bonding the conductive interconnect to the substrate contact. The semiconductor component can be used to form module components, underfilled components, stacked components, and image sensor semiconductor components.

Abstract: A back side illumination image sensor according to an embodiment includes: a device isolation region and a pixel region that are on a front side of a first substrate; a light sensor and a readout circuit that are on the pixel region; an interlayer dielectric layer and a metal line that are on the front side of the first substrate; a second substrate that is bonded to the front side of the first substrate on which the metal line is formed; a pixel isolating dielectric layer that is on the device isolation region at a back side of the first substrate; and a microlens that is on the light sensor at the back side of the first substrate

Abstract: A back side illumination image sensor according to an embodiment includes: a photosensitive device and a readout circuit on the front side of a first substrate; an interlayer dielectric layer on the front side of the first substrate; a metal line on the interlayer dielectric layer; a pad having a step on the interlayer dielectric layer; and a second substrate bonded with the front side of the first substrate over the interlayer dielectric layer, metal line, and pad.

Abstract: The present invention provides a semiconductor light emitting device capable of easily realizing stable output characteristics within a wide temperature range. The semiconductor light emitting device includes a semiconductor laser element, and a semiconductor photodiode having an absorption layer disposed on a semiconductor substrate, a second conductivity type region formed in a cap layer and the absorption layer, and a transmissive reflection film disposed on the back side of the semiconductor substrate. The semiconductor photodiode is mounted with the epitaxial layer side down, and the transmissive reflection film is irradiated with a laser beam emitted from the semiconductor laser element so that light reflected from the transmissive reflection film is used as output light, and transmitted light is received by the semiconductor photodiode and used for controlling the output of the semiconductor laser element.

Abstract: A backside illumination (BSI) image sensor having a light receiving part at the wafer or die backside, and a manufacturing method thereof, are disclosed. The method includes polishing the light receiving part so that a super via protrudes, forming a first insulating layer to cover the protruding super via and the light receiving part, forming a photoresist pattern on the first insulating layer to expose a pad region, etching the first insulating layer to form spacers at sides of the protruding super via, repeatedly forming a second insulating layer covering the spacers, the super via and the light receiving part and etching the second insulating layer so that the spacers increase in width and cover an upper surface of the light receiving part, and forming a metal pad in the pad region to contact the super via.

Abstract: A semiconductor wafer includes one or more back-illuminated image sensors each formed in a portion of the semiconductor wafer. One or more thinning etch stops are formed in other portions of the semiconductor wafer.

Abstract: An image sensor using a back-illuminated photodiode and a manufacturing method thereof are provided. According to the present invention, since a surface of the back-illuminated photodiode can be stably treated, the back-illuminated photodiode can be formed to have a low dark current, a constant sensitivity of blue light for all photodiodes, and high sensitivity. In addition, it is possible to manufacture an image sensor with high density by employing a three dimensional structure in which a photodiode and a logic circuit are separately formed on different substrates.

Abstract: A solid state imaging device having a back-illuminated type structure in which a lens is formed on the back side of a silicon layer with a light-receiving sensor portion being formed thereon. Insulating layers are buried into the silicon layer around an image pickup region, with the insulating layer being buried around a contact layer that connects an electrode layer of a pad portion and an interconnection layer of the surface side. A method of manufacturing such a solid-state imaging device is also provided.

Abstract: A photoelectric conversion device is provided which is capable of improving the light condensation efficiency without substantially decreasing the sensitivity. The photoelectric conversion device has a first pattern provided above an element isolation region formed between adjacent two photoelectric conversion elements, a second pattern provided above the element isolation region and above the first pattern, and microlenses provided above the photoelectric conversion elements with the first and the second patterns provided therebetween. The photoelectric conversion device further has convex-shaped interlayer lenses in optical paths between the photoelectric conversion elements and the microlenses, the peak of each convex shape projecting in the direction from the electro-optical element to the microlens.

Abstract: A backside-illuminated sensor including a semiconductor substrate. The semiconductor substrate has a front surface and a back surface. A plurality of pixels are formed on the front surface of the semiconductor substrate. At least one pixel includes a photogate structure. The photogate structure has a metal gate that includes a reflective layer.

Abstract: A backside illuminated image sensor includes a substrate, a backside passivation layer disposed on backside of the substrate, and a transparent conductive layer disposed on the backside passivation layer.

Abstract: In a rear surface incidence type CMOS image sensor having a wiring layer 720 on a first surface (front surface) of an epitaxial substrate 710 in which a photodiode, a reading circuit (an n-type region 750 and an n+ type region 760) and the like are disposed, and a light receiving plane in a second surface (rear surface), the photodiode and a P-type well region 740 on the periphery of the photodiode are disposed in a layer structure that does not reach the rear surface (light receiving surface) of the substrate, and an electric field is formed within the substrate 710 to properly lead electrons entering from the rear surface (light receiving surface) of the substrate to the photodiode. The electric field is realized by providing a concentration gradient in a direction of depth of the epitaxial substrate 710. Alternatively, the electric field can be realized by providing a rear-surface electrode 810 or 840 for sending a current.

Abstract: With this semiconductor device, the distortion and cracking of a thinned portion of a semiconductor substrate are prevented to enable high precision focusing with respect to a photodetecting unit and uniformity and stability of high sensitivity of the photodetecting unit to be maintained. A semiconductor device 1 has a semiconductor substrate 10, a wiring substrate 20, conductive bumps 30, and a resin 32. A CCD 12 and a thinned portion 14 are formed on semiconductor substrate 10. Electrodes 16 of semiconductor substrate 10 are connected via conductive bumps 30 to electrodes 22 of wiring substrate 20. Insulating resin 32 fills a gap between outer edge 15 of thinned portion 14 and wiring substrate 20 to reinforce the bonding strengths of conductive bumps 30. This resin 32 is a resin sheet that has been formed in advance so as to surround a periphery of a gap between thinned portion 14 and wiring substrate 20 except for portions of the periphery.

Abstract: An image sensor including photosensitive cells including photodiodes and at least one additional circuit with a significant heat dissipation including transistors. The image sensor is made in monolithic form and includes a layer of a semiconductor material having first and second opposite surfaces and including, on the first surface side, first regions corresponding to the power terminals of the transistors, the lighting of the image sensor being intended to be performed on the second surface side; a stack of insulating layers covering the first surface; a thermally conductive reinforcement covering the stack on the side opposite to the layer; and thermally conductive vias connecting the layer to the reinforcement.

Abstract: Disclosed herein is a solid-state imaging element which includes a plurality of drive signal inputs, a plurality of bus lines, and a plurality of vertical transfer register electrodes. In the solid-state imaging element, a charge accumulated in light-receiving elements in a pixel region is vertically transferred by the drive signals input to the electrodes. Each of the electrodes has a contact part connected to the second contact and having a width smaller than a width of the electrodes in the pixel region, and a blank region is formed between predetermined adjacent two of the contact parts so that a width of the blank region is larger than a distance between respective two of the contact parts other than the predetermined adjacent two of the contact parts. The first contact is disposed on the blank region.

Abstract: Provided are an image sensor and a method of forming the image sensor. The image sensor has a base multi-layered reflection layer interposed between a photodiode and an interlayer insulating layer. The photodiode has a first surface adjacent to the interlayer insulating layer and a second surface opposite the first surface. Here, external light is incident on the second surface of the photodiode. Also, the image sensor includes a sidewall multi-layered reflection layer that encloses the photodiode.

Abstract: An indirect connection to and across a photodiode array. The backside contact is used as one portion which connects to a capacitor. The capacitor forms a shunt across the bulk substrate, thus shunting across the series resistance of the substrate, and reducing the series resistance.

Abstract: An integrated circuit system including: providing an integrated circuit wafer having an integrated circuit side and a backside; mounting a protective adhesive on the integrated circuit side of the integrated circuit wafer; removing material from the backside of the integrated circuit wafer; and dicing the integrated circuit wafer through the protective adhesive to form an integrated circuit die.

Abstract: A backside-illuminated sensor including a semiconductor substrate. The semiconductor substrate has a front surface and a back surface. A plurality of pixels are formed on the front surface of the semiconductor substrate. At least one pixel includes a photogate structure. The photogate structure has a gate that includes a reflective layer.

Abstract: The present invention provides a back illuminated photodetector having a sufficiently small package as well as being capable of suppressing the scattering of to-be-detected light and method for manufacturing the same. A back illuminated photodiode 1 comprises an N-type semiconductor substrate 10, a P+-type impurity semiconductor region 11, a recessed portion 12, and a window plate 13. In the surface layer on the upper surface S1 side of the N-type semiconductor substrate 10 is formed the P+-type impurity semiconductor region 11. In the rear surface S2 of the N-type semiconductor substrate 10 and in an area opposite the P+-type impurity semiconductor region 11 is formed the recessed portion 12 that functions as an incident part for to-be-detected light. Also, the window plate 13 is bonded to the outer edge portion 14 of the recessed portion 12. The window plate 13 covers the recessed portion 12 and seals the rear surface S2 of the N-type semiconductor substrate 10.

Abstract: Provided is an apparatus that includes an integrated circuit located in a first region of a substrate having first and second opposing major surfaces and an alignment mark located in a second region of the substrate and extending through the substrate between the first and second surfaces.

Abstract: A structure for implementation of back-illuminated CMOS or CCD imagers. An epitaxial silicon layer is connected with a passivation layer, acting as a junction anode. The epitaxial silicon layer converts light passing through the passivation layer and collected by the imaging structure to photoelectrons. A semiconductor well is also provided, located opposite the passivation layer with respect to the epitaxial silicon layer, acting as a junction cathode. Prior to detection, light does not pass through a dielectric separating interconnection metal layers.

Abstract: A photodetector and a method for fabricating a photodetector. The photodetector may include a substrate, a buffer layer formed on the substrate, and an absorption layer formed on the buffer layer for receiving incident photons and generating charged carriers. An N-doped interface layer may be formed on the absorption layer, an N-doped cap layer may be formed on the N-doped interface layer, and a dielectric passivation layer may be formed above the cap layer. A P+ diffusion region may be formed within the cap layer, the N-doped interface layer and at least a portion of the absorption layer, and at least one contact may be formed on and coupled to the P+ diffusion region.

Abstract: An image sensor using a back-illuminated photodiode and a manufacturing method thereof are provided. According to the present invention, since a surface of the back-illuminated photodiode can be stably treated, the back-illuminated photodiode can be formed to have a low dark current, a constant sensitivity of blue light for all photodiodes, and high sensitivity. In addition, it is possible to manufacture an image sensor with high density by employing a three dimensional structure in which a photodiode and a logic circuit are separately formed on different substrates.

Abstract: An imaging sensor with an array of FET pixels and method of forming the imaging sensor. Each pixel is a semiconductor island, e.g., N-type silicon on a Silicon on insulator (SOI) wafer. FETs are formed in one photodiode electrode, e.g., a P-well cathode. A color filter may be attached to an opposite surface of island. A protective layer (e.g., glass or quartz) or window is fixed to the pixel array at the color filters. The image sensor may be illuminated from the backside with cell wiring above the cell. So, an optical signal passes through the protective layer is filtered by the color filters and selectively sensed by a corresponding photo-sensor.

Abstract: A backlit photodiode array includes a semiconductor substrate having first and second main surfaces opposite to each other. A first dielectric layer is formed on the first main surface. First and second conductive vias are formed extending from the second main surface through the semiconductor substrate and the first dielectric layer. The first and second conductive vias are isolated from the semiconductor substrate by a second dielectric material. A first anode/cathode layer of a first conductivity is formed on the first dielectric layer and is electrically coupled to the first conductive via. An intrinsic semiconductor layer is formed on the first anode/cathode layer. A second anode/cathode layer of a second conductivity opposite to the first conductivity is formed on the intrinsic semiconductor layer and is electrically coupled to the second conductive via.

Abstract: In a case when a structure of forming a p+ layer on a substrate rear surface side is employed in order to prevent dark current generation from the silicon boundary surface, various problems occur. According to this invention, an insulation film 39 is provided on a rear surface on a silicon substrate 31 and a transparent electrode 40 is further provided thereon, and by applying a negative voltage with respect to the potential of the silicon substrate 31 from a voltage supply source 41 to the insulation film 39 through the transparent electrode 40, positive holes are accumulated on a silicon boundary surface of the substrate rear surface side and a structure equivalent to a state in which a positive hole accumulation layer exists on aforesaid silicon boundary surface is to be created. Thus, various problems in the related art can be avoided.

Abstract: A solid-state imaging device having a light-receiving section that photoelectrically converts incident light includes an insulating film formed on a light-receiving surface of the light-receiving section and a film and having negative fixed charges formed on the insulating film. A hole accumulation layer is formed on a light-receiving surface side of the light-receiving section. A peripheral circuit section in which peripheral circuits are formed is provided on a side of the light-receiving section. The insulating film is formed between a surface of the peripheral circuit section and the film having negative fixed charges such that a distance from the surface of the peripheral circuit section to the film having negative fixed charges is larger than a distance from a surface of the light-receiving section to the film having negative fixed charges.

Abstract: An image sensor includes a circuit substrate, a plurality of isolation regions, a plurality of photoelectric converters, and an insulation layer. The isolation regions are formed in a pixel region having the photoelectric converters formed therein with each photoelectric converter being electrically isolated by the isolation regions. The insulation layer is formed in a pad region with a substantially same depth as the isolation regions. The isolation region and the insulation layer are simultaneously formed for efficient fabrication of the image sensor.

Abstract: To provide a back-illuminated type solid-state imaging device capable of color separation of pixels without using a color filter, and a camera module and an electronic equipment module which incorporate the solid-state imaging device. A solid-state imaging device including: a photoelectric conversion element PD formed in a semiconductor substrate 22; a reading-out part which reads out signal charges from the photoelectric conversion element PD formed on one surface side of the semiconductor substrate 22; the other surface of the semiconductor substrate 22 made to a light incidence surface; and a pixel which exclusively makes light of a specific wavelength or longer photoelectrically converted, by adjusting pn junction depths h2 [h2 r, h2 g, h2 b] between the photoelectric conversion element PD and an accumulation layer 28 on the light incidence surface side. A camera module and an electronic equipment module which incorporate the solid-state imaging device.

Abstract: A CMOS image sensor includes a plurality of pixel regions formed under a front surface of a substrate, and having photodiodes separated from each other by a field oxide, a multi-layered metal interconnection formed over the pixel regions of the front of the substrate, a bump connected to an uppermost metal interconnection of the multi-layered metal interconnection, a plurality of trenches formed in a backside of the substrate, wherein the trenches have different depths for each wavelength of light, and correspond to the respective pixel regions, and a glass covering the backside of the substrate.

Abstract: A backside illuminated CMOS image sensor having an silicon layer with a front side and a backside, the silicon layer liberates charge when illuminated from the backside with light, an active pixel circuitry located on the front side of the semiconductor layer, a pinned photodiode adjacent to the active pixel circuitry on the front side of the semiconductor layer and configured to collect charge liberated in the semiconductor layer, and an implant located in the semiconductor layer, underneath the active pixel circuitry, for allowing charge liberated in the semiconductor layer to drift from the backside of the semiconductor layer to the pinned photodiode on the front side of the semiconductor layer.

Abstract: An apparatus comprises: a substrate; a photodetector formed on an area of a surface of the substrate; an electrical contact formed on a portion of the photodetector; and a reflector formed over a portion of the photodetector distinct from the portion of the photodetector having the electrical contact formed thereon. The substrate, the photodetector, and the reflector are arranged so that an optical signal to be detected is incident on the photodetector from within the substrate, and at least a portion of the optical signal incident on the photodetector and transmitted thereby on a first pass is reflected by the reflector to propagate through the photodetector for a second pass.

Abstract: The present disclosure provides a backside illuminated semiconductor device. The device includes a substrate having a front surface and a back surface; a plurality of sensor elements formed in the substrate, each of the plurality of sensor elements is designed and configured to receive light directed towards the back surface; and a sensor isolation feature formed in the substrate, and disposed horizontally between two adjacent elements of the plurality of sensor elements, and vertically between the back surface and the front surface.

Abstract: Backthinning in an area selective manner is applied to CMOS imaging sensors 12 for use in electron bombarded active pixel array devices. A further arrangement results in an array of collimators 51 aligned with pixels 42 or groups of pixels of an active pixel array providing improved image contrast of such image sensor. Provision of a thin P-doped layer 52 on the illuminated rear surface provides both a diffusion barrier resulting in improved resolution and a functional shield for reference pixels. A gradient in concentration of P-doped layer 52 optimizes electron collection at the pixel array.

Abstract: An electronic equipment includes a light source, in which light of the light source is guided and emitted from an operation member having translucent properties via an optical waveguide, wherein a phosphor emitting visible light by being excited by the light from the light source is contained in a path through which the light of the light source is guided. A backlight structure in which a light source is provided in a printed substrate that is inside a casing having a waveguide plate, and light of the light source is transmitted through the waveguide plate and emitted, wherein a wavelength-converting phosphor that emits light by being excited by the light of the light source is provided in a waveguide path leading to a point where the light of the light source is transmitted through the waveguide plate and is emitted out, except the light source and the printed substrate.

Abstract: A backside-illuminated imaging device, which performs imaging by illuminating light from a back side of a semiconductor substrate to generate electric charges in the semiconductor substrate based on the light and reading out the electric charges from a front side of the semiconductor substrate, is provided and includes: a back-side layer including an back-side element on the back side of the semiconductor substrate; a front-side layer including an front-side element on the front side of the semiconductor substrate; a support substrate above the front-side layer; a spacer, one end of which comes in contact with the front-side layer and the other end of which comes in contact with the support substrate, to form a space having a uniform distance between the semiconductor substrate and the support substrate; and an adhesive filled in at least a part of the space between the surface-side element formation layer and the support substrate.

Abstract: A backside-illuminated sensor including a semiconductor substrate. The semiconductor substrate has a front surface and a back surface. A plurality of pixels are formed on the front surface of the semiconductor substrate. At least one pixel includes a photogate structure. The photogate structure has a gate that includes a reflective layer.

Abstract: A technique capable of stably releasing chips from a dicing tape, includes grinding a back surface of a semiconductor wafer, while adhering a pressure sensitive adhesive tape to a circuit forming surface of the semiconductor wafer formed with an integrated circuit, to achieve a predetermined thickness and forcibly oxidizing the back surface of the semiconductor wafer. Then, the pressure sensitive adhesive tape adhered to the circuit forming surface of the semiconductor wafer is released, and a dicing tape is adhered to the back surface of the semiconductor wafer. Further, the semiconductor wafer is divided by dicing it into individual chips, and then the back surface of the chip is pressed by way of the dicing tape, thereby releasing the chips from the dicing tape.

Abstract: A photodetector circuit incorporates an APD detector structure (10) comprising a p? silicon handle wafer (12) on which a SiO2 insulation layer (14) is deposited in known manner. During manufacture a circular opening (16) is formed through the insulation layer (14) by conventional photolithography and etching, and an annular p+ substrate contact ring (18) is implanted in the handle wafer (12) after opening of the window (16). The APD itself is formed by implantation of a p region (20) and an n+ region (22). After the various implantation steps a metallisation layer is applied, and annular metal contacts are formed by the application of suitable photolithography and etching steps, these contacts comprising an annular contact (26) constituting the negative terminal and connected to the p+ substrate contact ring (18), an annular metal contact (28) constituting the positive terminal and connected to the n+ region (22) of the APD, and source and drain contacts (30) and (32) (not shown in FIG.

Abstract: A backside illuminated CMOS image sensor having an silicon layer with a front side and a backside, the silicon layer liberates charge when illuminated from the backside with light, an active pixel circuitry located on the front side of the semiconductor layer, a pinned photodiode adjacent to the active pixel circuitry on the front side of the semiconductor layer and configured to collect charge liberated in the semiconductor layer, and an implant located in the semiconductor layer, underneath the active pixel circuitry, for allowing charge liberated in the semiconductor layer to drift from the backside of the semiconductor layer to the pinned photodiode on the front side of the semiconductor layer.

Abstract: A backside illuminated solid-state imaging device is provided and includes: a p-type semiconductor substrate; an imaging region that receives a subject light through a back side of the p-type semiconductor substrate to accumulate a signal corresponding to an amount of the received light; a signal reading element disposed in a front side of the p-type semiconductor substrate, the signal reading element reading out the signal from the imaging region; and an n-well region disposed in the front side of the p-type semiconductor substrate and in a periphery of the imaging region, the n-well region being biased to a positive voltage.

Abstract: The present invention provides a back illuminated photodetector having a sufficiently small package as well as being capable of suppressing the scattering of to-be-detected light. A back illuminated photodiode 1 comprises an N-type semiconductor substrate 10, a P+-type doped semiconductor region 11, a recessed portion 12, and a coating layer 13. In the surface layer on the upper surface S1 side of the N-type semiconductor substrate 10 is formed the P+-type doped semiconductor region 11. In the rear surface S2 of the N-type semiconductor substrate 10 and in an area opposite the P+-type doped semiconductor region 11 is formed the recessed portion 12 that functions as an incident part for to-be-detected light. Also, on the rear surface S2 is provided the coating layer 13 for transmitting to-be-detected light that is made incident into the recessed portion 12.

Abstract: A method for improving sensitivity of backside illuminated image sensor. A substrate having a first conductivity type and a first potential. A depletion region having a second conductivity type is formed within the substrate. The depletion region is extended. The thickness of the substrate is reduced. First type conductivity ions having a second potential are implanted at backside surface of the substrate to form a doping layer. Laser annealing on the doping layer is performed to activate the first type conductivity ions.

Abstract: An image sensor including photosensitive cells including photodiodes and at least one additional circuit with a significant heat dissipation including transistors. The image sensor is made in monolithic form and includes a layer of a semiconductor material having first and second opposite surfaces and including, on the first surface side, first regions corresponding to the power terminals of the transistors, the lighting of the image sensor being intended to be performed on the second surface side; a stack of insulating layers covering the first surface; a thermally conductive reinforcement covering the stack on the side opposite to the layer; and thermally conductive vias connecting the layer to the reinforcement.