JP2010039659A - Photo-sensor device, and image display device with authentication function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive biometric authentication apparatus capable of reducing the occurrence ratio of principal refusal, and reducing the occurrence ratio of impersonation and others acceptance. <P>SOLUTION: This biometric authentication apparatus is configured of the transmission source of electromagnetic waves for detection and a sensor device for detecting electromagnetic waves including the information of the features of a living body. The transmission source is configured of two more types of transmission sources having different wavelength bands, and the sensor device is provided with an area sensor part in which a plurality of sensor elements for detecting the electromagnetic waves are two-dimensionally arrayed; an operation control circuit group of the area sensor part; and an arithmetic processing circuit group for performing the arithmetic processing of an output from the area sensor part. The area sensor part is configured of two or more types of sensor groups whose detection wavelength bands are different. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical sensor device having a thin film optical sensor element formed on an insulating film substrate, and in particular, a biometric authentication device including an optical sensor array used as a near infrared detection device for biometric authentication, and an optical sensor array The present invention relates to an image display device in which an authentication function, a touch panel function, and an input function are incorporated in a display panel unit, such as a liquid crystal display, an organic EL (Electro Luminescence) display, an inorganic EL display, an EC (Electro Chromic) display, and the like.

  Biometric authentication is attracting attention as an effective means for authenticating individuals in accordance with the progress of the information society. The features of biometric authentication are convenience and safety, and it is known that there is no forgotten or lost password or IC card, and the possibility of theft or forgery is relatively low.

  The main biometric authentication methods are those that target behavioral features such as handwriting and voice, and those that target physical features such as finger veins, palm (back of hand) veins, fingerprints, facial contours (face part placement), and irises. (See Non-Patent Document 1 and Non-Patent Document 2 below). The characteristics required for the authentication target are: a. Good operability, b. Small amount of data for authentication, c. High accuracy or predictability, d. System management costs are reduced E. Good stability, etc. There is no advantage in any of these indicators, and all of the certification targets are pros and cons. The authentication target is often detected as an image pattern by electromagnetic waves such as visible light and near-infrared light, and the pattern and a pre-registered pattern are collated to determine whether they match or not.

  Currently, the biometric authentication system is used as a key for entrance / exit management, a login system such as a PC, and a bank ATM. In the future, it is expected to be applied to mobile terminal devices such as mobile phones and PDAs, and in-vehicle unlock systems. Especially in the ubiquitous society, it is expected that electronic commerce such as stock trading and deposits and savings will be done anytime and anywhere via mobile terminal devices, and biometric authentication is expected to become the mainstream personal authentication key .

  In these applications, since there is not enough space for the installation of the authentication device, it is desired to make it thinner and more compact. For example, in the current finger vein authentication system, a CCD camera is used as a vein image capturing device. In the case of a CCD camera, the area of the sensor array is as small as a few mm square, and a reduction optical system is required to capture the area required for authentication. This makes it difficult to reduce the thickness.

  In recent years, in the field of liquid crystal displays, as a system-in-display technique, a technique for incorporating an array of visible light range photosensors into a panel has been proposed, and a technique for applying this to fingerprint authentication has been reported (Non-Patent Document 2 below) reference). A feature of this technique is that a large-area photosensor array can be formed on an inexpensive insulating substrate. By reducing the area, a reduction optical system becomes unnecessary, and a reduction in thickness can be realized. Further, since the sensor element can be formed in the TFT manufacturing process in the liquid crystal display, it is advantageous for mounting the device on the information terminal device.

  In the biometric authentication, a means for detecting one kind of authentication object by one kind of method is common, but this means has a problem that (1) false rejection occurs. For example, in fingerprint authentication, when authentication is performed with a wet hand, the imaging data changes due to a change in reflectance. In vein authentication, there are cases where the absorption of light of a certain wavelength is weak due to individual differences. Another problem of this measure is (2) impersonation and the possibility of false acceptance. For example, in fingerprint authentication, a glove with a fingerprint pattern of another person can be authenticated as another person. The problems (1) and (2) are difficult to solve by means for detecting one type of authentication object by one type of method. If the pattern matching ratio (authentication threshold) for authentication is set high, the problem (2) is solved, but the problem (1) becomes obvious. Conversely, if the authentication threshold is set low, the problem (1) is solved, but the problem (2) becomes obvious.

  As a means for solving the above problems (1) and (2) at the same time, there is a method of using a plurality of authentication targets. In this method, the authentication threshold value is lowered for each authentication target, and only when the authentication threshold is exceeded in all authentication operations. As another means for simultaneously solving the above problems (1) and (2), there is a method of reading one authentication object with a plurality of wavelengths. Either lower the authentication threshold at each wavelength and pass only when the authentication threshold is exceeded in all authentication work, or set the authentication threshold at each wavelength higher, and either authentication work Is a method of passing if the authentication threshold is exceeded. When these authentication means are selected, the necessary device specification is an authentication device composed of a plurality of wavelength light sources and corresponding sensor devices (or sensor elements). For example, when fingerprints and veins are selected using a method that uses multiple authentication targets, the former authentication requires a light source in the visible light region, and the latter authentication requires a light source in the near infrared region and a corresponding sensor device (sensor element). become. Further, in the method of reading one authentication target with a plurality of wavelengths, when a vein is selected, a light source with a plurality of wavelengths belonging to the near infrared region and a sensor device (sensor element) corresponding thereto are required.

As an apparatus that meets this specification, for example, as in the apparatus described in Patent Document 1 below, a plurality of illuminations (light sources) having different wavelengths are used, and light emission or light amount adjustment is selectively performed to achieve one authentication. It consists of a device that performs personal authentication with the target (iris pattern) and a light source of two wavelengths and one sensor device as described in Patent Document 2 below, and selectively emits and adjusts the light source. There is a personal authentication device that reads a fingerprint and a vein image with one type of sensor device. Although the application method is different, Patent Document 3 below also describes a similar device.
Kaori Horiuchi, Nikkei Byte, pp.28-47, (2005) Motonobu Kawai, Nikkei Electronics, pp.61-66, (2005) JP 2006-31185 A JP 2007-179434 A JP 2006-285487 A

  A characteristic of the above-described apparatus is that a single type of sensor apparatus (sensor element) reads signals of a plurality of wavelengths. However, since the wavelength sensitivity characteristics of sensor devices (sensor elements) generally differ depending on the type, there arises a problem that accuracy is lowered for a certain authentication target (a certain wavelength), and the problems (1) and (2) described above are simultaneously It becomes difficult to solve.

  The device specification for solving this is a personal authentication device including a plurality of wavelength light sources and a plurality of sensor devices (sensor elements) corresponding thereto. For example, as described in Patent Document 3, a light source that outputs two different wavelengths and two sensor devices that detect light of the respective wavelengths may be provided, and a device that performs authentication using a fingerprint and a vein may be used.

  With this apparatus specification, the above problems (1) and (2) can be solved simultaneously. However, the sweep type sensor device described in Patent Document 3 has a problem that reading accuracy is poor and user convenience is poor. Further, since each sensor device is formed (installed) in a separate area, improvement is required for mounting on a portable terminal with a small installation space. The present invention has been made in view of the above-described circumstances.

  An object of the present invention is to provide a biometric authentication apparatus that is low in cost and has a reduced rate of occurrence of false rejection, impersonation, and a reduced rate of occurrence of false acceptance.

  The present invention is a personal authentication device comprising two or more types of light sources that output different wavelengths and two or more types of sensor devices (sensor elements) having different detection wavelength bands corresponding to the light sources. Two or more types of sensor elements having different detection wavelength bands are formed in the same region so as to be arranged in a matrix, and a sensor driver circuit (if necessary) is formed on the periphery of the region. , Pixel circuits and other circuits) are formed on the same substrate. As a result, the proportion of false rejection can be reduced, and the proportion of impersonation (False acceptance) can be reduced.

  In the present invention, two or more types of sensor elements having different detection wavelength bands on the same insulating substrate are formed in the same region so that each is arranged in a matrix, and the periphery of the region is A sensor device in which a sensor driver circuit (a pixel circuit and other circuits as necessary) is formed is provided. Thereby, the ratio of false rejection can be reduced, and the ratio of impersonation and false acceptance can be reduced. In addition, an inexpensive authentication device or an image display device incorporating the authentication device can be provided.

  The above-described configuration is merely an example, and the present invention can be modified as appropriate without departing from the technical idea. Further, examples of the configuration of the present invention other than the above-described configuration will be clarified from the entire description of the present specification or the drawings.

  According to the biometric authentication device of the present invention, the generation rate of false rejection can be reduced at low cost, and the generation rate of impersonation (False acceptance) can be reduced.

  Other effects of the present invention will become apparent from the description of the entire specification.

  Embodiments of the present invention will be described with reference to the drawings. In each drawing and each example, the same or similar components are denoted by the same reference numerals and description thereof is omitted.

<Example 1>
(Configuration of optical sensor device etc.)
1A to 1D are schematic plan views of an optical sensor device SS constituting an authentication device according to the present invention.

  In each of FIGS. 1A to 1D, an area sensor unit TS in which a first sensor element SA and a second sensor element SB for detecting electromagnetic waves are two-dimensionally arranged, and an area sensor unit TS An operation control circuit group CNC arranged at the periphery and an arithmetic circuit group CNL for arithmetic processing of the output from the area sensor unit TS are configured. FIGS. 1A to 1D show that the arrangement states of the first sensor elements SA and the second sensor elements SB are different in the area sensor unit TS. This arrangement will be described in detail later.

  The first sensor element SA and the second sensor element SB are two-dimensionally arranged in the area of the same area sensor unit TS, and detect different electromagnetic waves. The upper surface of the first sensor element SA and the second sensor element SB does not require an optical filter film for reducing the wavelength, such as a color filter and a wavelength cut filter, so that a high output can be secured and the mounting cost thereof is unnecessary. Yes. The area of the area sensor unit TS depends on the authentication target (for example, a finger), but is generally 1 cm 2 or more. For this reason, a reduction optical system such as a CCD or CMOS camera is not necessary. Further, it is possible to realize an optical sensor device SS having a device thickness of about 5 mm or less. In addition, there is an effect that it is possible to suppress the occurrence of distortion or the like of the peripheral image due to the reduction optical system.

  Here, the sensor elements (first sensor element SA, second sensor element SB) are composed of the equivalent circuit shown in FIG. 2A, and are composed of a photoelectric conversion unit LCH composed of a diode and a capacitor composed of a capacitor. The charge accumulation unit AML accumulates the charges generated in the above and the readout unit WRT which is composed of a thin film transistor and amplifies the accumulated charge and reads it as a signal. In this embodiment, the photoelectric conversion unit LCH is composed of a diode, the charge storage unit ALM is composed of a capacitor, and the readout unit WRT is composed of a thin film transistor. However, the present invention is not limited to this. It can replace with these and can be used. In FIG. 2A, reference numeral GL indicates a gate line, reference numeral RS indicates a reset line, and reference numeral WT indicates a readout line.

  The sensor elements (first sensor element SA, second sensor element SB) shown in FIG. 2A are arranged in a matrix form in the area sensor unit TS, for example, as shown in FIG. The line GL is common to the sensor elements arranged in the row direction, and the reset line RS and the readout line WT are common to the sensor elements arranged in the column direction. In this case, a region occupied by each sensor element (a region surrounded by a dotted line in the figure) is referred to as a sensor pixel in this specification.

  Returning to FIG. 1, the arrangement state of the first sensor element SA and the second sensor element SB in the area sensor unit TS will be described below.

  As shown in FIG. 1A, the first sensor elements SA and the second sensor elements SA have the same sensor pixel shape, and are alternately arranged in the left-right and up-down directions.

  In the figure, the sensor elements with hatched lines are indicated as second sensor elements SB, and the sensor elements without hatched lines are indicated as first sensor elements AS. In the case of the arrangement of the first sensor element SA and the second sensor element SA, since the sensor pixels have the same shape, the arrangement is a matrix. With a simple timing chart configuration, the optical sensor device SS can be configured. The optical sensor device SS shown in FIG. 1B shows, for example, a case where there are two or more types of authentication targets and different required resolutions. In FIG. 1B, the second sensor elements SB are arranged in the vertical direction in the drawing at the left end portion, the central portion, and the right end portion in the drawing of the area sensor portion TS, and the first sensor element is provided in the remaining other portions. SA is arranged.

  In such an arrangement, for example, the first sensor element SA is used for an authentication target (for example, fingerprint authentication) that requires high resolution, and the second sensor element SB is used for an authentication target (for example, vein authentication) that may have a low resolution. It is used as. By arranging the second sensor elements SB in this way, it is possible to avoid reading unnecessary resolution data and performing unnecessary processing. Further, since the number of wirings can be reduced by sharing the gate line GL or the readout line WT, there is an effect that the aperture ratio can be improved when incorporated in an image display device or the like. Further, in the case where there are two or more types of authentication targets and the required resolutions are different, for example, the pixel size of the second sensor element SB is made larger than the pixel size of the first sensor element AS as shown in FIG. It is also possible to change the shape of sensor pixels of these sensor elements by increasing the size. In the case of FIG. 1 (c), the second sensor elements SB are arranged at regular intervals in the area sensor unit TS. Although it is necessary to devise wiring, in this case also, it is possible to avoid unnecessary processing by reading unnecessary resolution data. Furthermore, the second sensor element SB having a large pixel size can increase the photoelectric conversion unit LCH, thereby improving the sensor output. The optical sensor device SS shown in FIG. 1D is suitable when, for example, the distance between the upper surface of the area sensor unit TS and the authentication object varies depending on the position of an object having a curvature such as a finger. It has become. That is, when it is necessary to capture a wider image pattern in terms of region, it is desirable to change the resolution between the central portion and the peripheral portion of the area sensor unit TS. In FIG. 1D, the first sensor element SA is arranged so that the high resolution is obtained in the central part of the area sensor part TS, and the second sensor element SB is the central part of the area sensor part TS. The sensor elements are arranged so that the resolution is low and the peripheral edge is low resolution. For example, when fingerprints and veins are to be authenticated, such an optical sensor device SS is a first sensor for a fingerprint that requires a high-resolution image in a region in the vicinity of the contact portion between the finger and the device. With the element SA, the second sensor element SB is used for a vein that requires a wide-area image and can be authenticated even at a relatively low resolution.

  FIGS. 3A to 3C are configuration diagrams showing an embodiment in the case where a sweep type photosensor device is configured in the area sensor unit TS, respectively. According to such an embodiment, compared to a case where a plurality of optical sensor devices are separately installed, installation space can be omitted, mechanical reliability can be ensured, and costs can be reduced.

  3A to 3C, the optical sensor device SS places an object (for example, a finger) in the center of the area sensor unit TS so as to be parallel to the arrow A direction in the drawing, and the first sensor element An object to be read by SA (for example, a vein image) is imaged. Subsequently, a finger is pulled in the direction of the arrow A, and an object to be read by the sensor element B (for example, a fingerprint image) is picked up at that time.

  FIG. 3A shows that the second sensor elements SB are arranged side by side in the direction perpendicular to the arrow A direction at the center of the area sensor unit TS. In the other remaining areas of the area sensor unit TS, the first sensor elements AS are arranged. FIG. 3B shows that the second sensor elements SB are arranged side by side in a direction perpendicular to the arrow A direction at one end side in the arrow A direction of the area sensor unit TS. In the other remaining areas of the area sensor unit TS, the first sensor elements AS are arranged. Compared with the case of FIG. 3A, there is an effect that images to be read by the first sensor element SA are continuously formed. FIG. 3C is that the pixel size of each second sensor element SB is larger than the pixel size of the first sensor element AS in the configuration of FIG. This is effective when it is desired to increase the output from each second sensor element SB. 3A to 3C, the second sensor elements SB are respectively drawn in two rows in the area sensor unit TS. However, in practice, it is arranged in about 1 to 10 columns for an array of 100 rows or more.

  In each of the above-described embodiments, the sensor elements arranged in the area sensor unit TS are shown for two types of cases: the first sensor element AS and the second sensor element BS. However, for example, three or more types can be used depending on the authentication target or the number of reading wavelengths.

  FIGS. 4A to 4C show another embodiment of the present invention, in which at least the area sensor unit TS is formed on an insulating substrate such as a glass substrate.

  In FIG. 4A, the area sensor unit TS is formed on the insulating substrate SUB1, the operation control circuit group CNC and the arithmetic processing circuit group CLN are configured by LSI chips, and these are mounted on another substrate SUB2. It is made up. By doing in this way, the area sensor part TS can be formed in the cheap insulating substrate SUB1, and the apparatus cost can be reduced. FIG. 4B shows that the area sensor unit TS, the operation control circuit group CNC arranged at the periphery of the area sensor unit TS, and the arithmetic processing circuit group CLN are configured on the same insulating substrate SUB1. Yes. By doing in this way, since a terminal connection part can be reduced, in addition to cost reduction, the mechanical reliability of an apparatus can also be improved. FIG. 4C shows that the area sensor unit TS and a part of the operation control circuit group CNC are formed on the insulating substrate SUB1, and the remaining operation control circuit group CNC and arithmetic processing circuit group CLN are configured by LSI chips. These are configured so as to be mounted on another substrate SUB2.

  FIG. 5 is a cross-sectional view showing an embodiment of a biometric authentication device including the above-described optical sensor device SS. In this embodiment, for example, the case where the authentication object is a vein image and a fingerprint image of a finger (indicated by reference numeral FG in FIG. 5) is shown.

  The biometric authentication apparatus shown in FIG. 5 includes a first electromagnetic wave transmission source MA and a second electromagnetic wave transmission source MB, and each generates electromagnetic waves having different wavelengths.

  In the optical sensor device SS, the first sensor element SA and the second sensor element SB are formed as described above, and the first sensor element SA has sensitivity to light having a wavelength generated by the first electromagnetic wave transmission source MA. The two-sensor element SB has sensitivity to light having a wavelength generated by the second electromagnetic wave transmission source MB. The sensor substrate SSB is composed of a silicon substrate or an insulating substrate. In FIG. 5, the transmission source control circuit OCC and another circuit group ONC are formed on the back side of the sensor substrate SSB.

  FIG. 6A is a graph showing that the first sensor element SA has sensitivity in a wavelength band of, for example, 700 to 1000 nm. FIG. 6B is a graph showing that the second sensor element SB has sensitivity in a wavelength band of, for example, 500 to 700 nm. When the signal electromagnetic wave A derived from the first electromagnetic wave transmission source MA and the signal electromagnetic wave B derived from the second electromagnetic wave transmission source MB sent from the authentication object have spectra as shown in FIGS. 6 (a) and 6 (b), respectively. Since the wavelength sensitivity characteristics of the first sensor element SA and the second sensor element SB are different, signal interference does not occur even when electromagnetic waves are generated simultaneously. That is, according to the biometric authentication device of the present invention, the signal electromagnetic waves A and B can be detected simultaneously. When the authentication target is a vein image and a fingerprint image, the former is imaged by the first electromagnetic wave transmission source MA and the first sensor element SA, and the latter is imaged by the second electromagnetic wave transmission source MB and the second sensor element SB. .

  In the above, when the authentication target is a vein image and a fingerprint image, it is assumed that there are two types of detection wavelengths and sensor elements. However, it is possible to set three or more types as required, such as the number of authentication targets. . Further, two or more types of electromagnetic waves for detection having different wavelength bands and two or more types of sensor elements for detecting them can be designed to detect the characteristics of the same living body.

(Production method)
Next, on an insulating substrate, an area sensor unit composed of two or more types of sensor elements having different wavelength sensitivities and a switch element (hereinafter sometimes referred to as a TFT) composed of thin film transistors constituting a peripheral circuit thereof. One embodiment of the method will be described. A series of steps of this manufacturing method are shown in FIGS. 7A to 7D, FIGS. 8E to 8G, and FIGS. 9H to 9J.

  First, as shown in FIG. 7A, a silicon nitride film as a lower base film GRL1 and a silicon as an upper base film GRL2 are formed on an insulating substrate SUB suitable for glass, for example, by chemical vapor deposition (CVD). Oxide films are sequentially formed. Then, a polysilicon film is formed as the semiconductor film PS on the upper surface of the upper base film GRL2. The base films GRL1 and GRL2 formed of the first two layers (silicon nitride film and silicon oxide film) play a role of preventing contamination from the insulating substrate SUB. The polysilicon film may be formed directly by CVD, but after forming an amorphous silicon film with a low hydrogen content, it may be formed by melting and solidifying with an excimer laser, solid laser, rapid thermal processing (RTA), or the like. There is a method of forming by solid phase growth using furnace annealing, RTA, infrared laser, or the like. A photoresist is applied to the upper surface of the semiconductor film PS, and a patterned photoresist film RES is formed by a photolithography process.

  Next, as shown in FIG. 7B, the semiconductor layer PS is etched using the photoresist film RES as a mask, and the photoresist film RES is removed. The semiconductor film PS patterned in an island shape remains on the upper surface of the upper base film GRL2.

  Next, as shown in FIG. 7C, a gate insulating film GI and a metal film MTL for forming a gate electrode are sequentially formed so as to cover the semiconductor film PS. As the gate insulating film GI, it is desirable to use a silicon oxide film or a silicon nitride film. The metal film MTL is not necessarily limited to a metal film, and a silicon film having a low resistance by introducing a high-concentration impurity may be used. Then, a photoresist is applied on the upper surface of the metal film MTL, and a patterned photoresist film RES is formed by a photolithography process.

Next, as shown in FIG. 7D, the metal film MTL is etched using the photoresist film RES as a mask. The remaining metal film MTL is formed as the gate electrode GT. Thereafter, ion implantation is performed using the photoresist film RES and the gate electrode GT as a mask to form source / drain regions SD in the semiconductor layer PS.

  In this step, only one kind of TFT is formed (NMOS or PMOS) because a kind of impurity is introduced. However, a CMOS structure can be obtained by adding a photolithography and ion implantation process. Using the TFT as a switch element, a readout portion (when the TFT is employed) in the sensor pixel and a peripheral circuit are formed. Peripheral circuits composed of TFTs are an operation control circuit group arranged at the periphery of the area sensor unit, a circuit group for arithmetic processing of the output from the area sensor unit, a switch of the image display unit as necessary, and a drive circuit It is most ideal to be a group, but some of them may be supplemented with an LSI chip depending on the required performance.

  Next, as shown in FIG. 8E, by performing laser annealing or furnace annealing treatment, the introduced impurity in the semiconductor film PS is activated, and then an insulating protective film PAS1 is formed. Thus, a patterned wiring metal film CNL is formed. The wiring metal film CNL is electrically connected to the source / drain regions of the thin film transistor through through holes formed in the insulating protective film PAS1 and the gate insulating film GI. The wiring metal film CNL functions as a lower electrode for the sensor at the same time as the wiring. The wiring metal film CNL may be a silicon film in which a high-concentration impurity is introduced to reduce resistance instead of the metal film.

  Next, as shown in FIG. 8F, an insulating protective film PAS2 is formed, and a patterned photoresist film RES is formed by a photolithography process. The photoresist film RES has an opening formed in the sensor portion.

  Next, as shown in FIG. 8G, an n-type semiconductor layer nAS, an i-type semiconductor layer iAS, and a p-type semiconductor layer pAS made of amorphous silicon are successively and sequentially formed by CVD. These film thicknesses are controlled by the film formation time. In the semiconductor layer, the order of n-type and p-type can be changed depending on the combination of the upper and lower electrodes. Subsequently, a transparent conductive film TCN is formed thereon, and a patterned photoresist film RES is formed on the upper surface of the transparent conductive film TCN by a photolithography process. The material of the transparent conductive film TCN is generally ITO or ZnO, but it may be SnO or an organic high conductivity material as long as it has low resistance and high transmittance in the visible-near infrared region (400-1000 nm).

  Next, as shown in FIG. 9H, the first sensor element SA including the photoelectric conversion portion of the PIN diode is formed by etching using the photoresist film RES shown in FIG. 8G as a mask. Further, an n-type semiconductor layer nAS, an i-type semiconductor layer iAS, a p-type semiconductor layer pAS, and a transparent conductive film TCN made of amorphous silicon are successively formed by CVD. Here, the i-type semiconductor layer iAS is formed to be thinner than the i-type semiconductor layer iAS in the first sensor element SA.

  Next, as shown in FIG. 9I, the second sensor element SB including the photoelectric conversion portion of the PIN diode is formed by etching using the photoresist film RES shown in FIG. 9H as a mask.

  For the formation of the photoelectric conversion part of the second sensor element SB, in order to ensure the processing accuracy of the photoelectric conversion part of the first sensor element SA, it is preferable to select etching having a large selection ratio between the transparent conductive film and the amorphous silicon layer. If the selection ratio cannot be obtained, an insulating film having a large selection ratio is formed on the photoelectric conversion part of the first sensor element SA, and a contact hole is formed in the photoelectric conversion part of the second sensor element SB with photolithography. A photoelectric conversion part of the second sensor element SB may be formed.

  Finally, as shown in FIG. 9J, the insulating protective film PAS3 is formed and the connection points are processed to complete the process.

  In this manufacturing method, sensitivity adjustment is performed in the first sensor element SA and the second sensor element SB by changing the film thickness of each i-type semiconductor layer iAS. The first sensor element SA has a larger thickness of intrinsic amorphous silicon than the second sensor element SB. In this case, since the absorption on the long wavelength side increases as the film thickness is increased, the first sensor element SA has sensitivity on the high wavelength side, and the second sensor element SB has sensitivity on the low wavelength side. Thus, desired wavelength characteristics are obtained by adjusting the film thickness.

<Example 2>
Next, another embodiment of a method of manufacturing an area sensor unit composed of two or more types of sensor elements having different wavelength sensitivities and a peripheral circuit on the insulating substrate will be described with reference to FIGS. This will be explained using. This manufacturing method is performed through the steps of FIG. 8 (f) and then sequentially through FIGS. 10 (a), 10 (b), 11 (c), and (d).

For this reason, FIG. 8 (g) and FIG. 10 (a) are shown as the same figure, and the process after FIG. 10 (b) will be described in the following description.

  As shown in FIG. 10 (b), the photoelectric conversion portion (herein, PIN type diode is taken as an example) of the first sensor element SA is processed into an island shape by a photolithography process, and then n made of amorphous silicon is formed by CVD. The n-type semiconductor layer nAS, the i-type semiconductor layer iAS, and the p-type semiconductor layer pAS are continuously formed. Here, the p-type semiconductor layer pAS is formed with a film thickness larger than that of the p-type semiconductor layer pAS of the first sensor element SA. Subsequently, a transparent conductive film TCN is formed thereon. A patterned photoresist film RES is formed on the upper surface of the transparent conductive film TCN by a photolithography process.

  Next, as shown in FIG. 11C, etching is performed using the photoresist film RES shown in FIG. 10B as a mask, and the photoelectric conversion portion (PIN type diode) of the second sensor element SB is formed in an island shape. To process. In the island processing of the photoelectric conversion part of the second sensor element SB, in order to ensure the processing accuracy of the photoelectric conversion part of the first sensor element SA, when etching with a large selection ratio between the transparent conductive film and the amorphous silicon layer is selected. Good. If the selection ratio cannot be obtained, an insulating film having a large selection ratio is formed on the photoelectric conversion part of the first sensor element SA, and a contact hole is formed in the photoelectric conversion part of the second sensor element SB with photolithography. A photoelectric conversion part of the sensor element B may be formed.

  Finally, as shown in FIG. 11D, an insulating protective film PAS3 ′ is formed, and the connection points are processed to complete.

  In this manufacturing method, sensitivity adjustment is performed by changing the film thickness of the p-type semiconductor layer pAS. The film thickness of the p-type amorphous silicon is larger in the second sensor element SB than in the first sensor element SA. In this case, since light absorption on the short wavelength side occurs in the surface layer portion, when the p-type amorphous silicon film thickness is increased, the generated charges due to the short wavelength are generated in the p-type amorphous silicon film and immediately disappear. The second sensor element SB has sensitivity on the high wavelength side, and the first sensor element SA has sensitivity on the low wavelength side. A desired wavelength characteristic is obtained by adjusting the film thickness.

<Example 3>
FIGS. 12A to 12E each show a layout when the biometric authentication device shown in the first embodiment is mounted on an image display device so that the image display device has a personal authentication function. It is an example.

  FIG. 12A illustrates an image display device PNL with a personal authentication function in which an area sensor unit TS is installed in a region different from the pixel display unit AR on the surface on which the image display unit AR is formed. FIG. 12B shows an image display device PNL with a personal authentication function in which an area sensor unit TS is installed in a region where the image display unit AR is formed. This can be realized by forming TFTs, PIN diodes, and capacitors of the area sensor unit on the substrate on which the image display unit AR is formed. In FIG. 12C, the area sensor unit TS and the image display unit AR are formed on the same insulating substrate SUB1 with different regions, and are arranged on the substrate SUB2 in which the peripheral circuit PRC is formed on the insulating substrate SUB1. Thus, the image display device PNL with a personal authentication function is configured. In FIG. 12D, the area sensor unit TS, the image display unit AR, and the first peripheral circuit PRC1 are formed on the same insulating substrate SUB, and the second peripheral circuit PRC2 is formed on the insulating substrate SUB1. An image display device PNL with a personal authentication function is configured by being arranged on the formed substrate SUB2. FIG. 12E shows that the area sensor unit TS is formed in the image display unit AR on the surface of the substrate SUB1, and the substrate SUB1 is arranged on the substrate SUB2 including the peripheral circuit PRC to constitute the image display device PNL with a personal authentication function. Has been. In this embodiment, the peripheral circuit PRC is formed on the peripheral portion of the substrate SUB2, but at least a part of the peripheral circuit PRC is formed on the substrate SUB1 around the image display unit AR (area sensor unit TS). It may be configured. The two or more types of electromagnetic wave generation sources may be installed so as to be included in the backlight of the image display device using, for example, an LED or the like, or may be separately installed at the peripheral portion.

<Example 4>
FIGS. 13A to 13D respectively show the arrangement of a plurality of types of sensors and pixels when the area sensor unit TS is formed in the region of the pixel display unit AR as shown in FIG. 12E, for example. It is the Example which showed the structure of these.

  In FIG. 13A, the pixel shape of the plurality of types of sensors is the same as the shape of the pixel pixel, and the plurality of types of sensors are arranged almost evenly dispersed in the pixel pixel. In the case of this arrangement, each pixel is in a matrix form, and the wiring connected to each pixel can have a simple configuration. FIG. 13B is similar to FIG. 13A, and different portions are obtained by making the sensor pixel shape of at least one type of sensor element larger than the pixel pixel shape, such as the second sensor element SB. It is arranged. Such an arrangement is desirable when there are two or more types of authentication targets and different required resolutions. FIG. 13C incorporates the above-described sweep type sensor. For example, at least one type of sensor element group such as the second sensor element SB has 100 rows or more as described in FIG. About 1 to 10 rows are arranged with respect to the arrangement. Note that in FIG. 13C, the first sensor elements SA are arranged almost evenly dispersed in the pixel pixels. In FIG. 13D, at least one type of sensor element group is arranged along one side of the image display unit AR, for example, as the second sensor element SB, in the image display unit AR. In FIG. 13 (d), the first sensor elements SA are arranged substantially evenly dispersed in the pixel pixels.

It is a schematic plan view of the optical sensor apparatus which comprises the authentication apparatus of this invention. FIG. 3 is an equivalent circuit diagram in which sensor elements and the sensor elements are arranged in a matrix. It is a schematic plan view of the optical sensor apparatus which comprises the authentication apparatus of this invention, and is a block diagram which shows the Example at the time of comprising a sweep type optical sensor apparatus in an area sensor part. It is a schematic plan view of the optical sensor apparatus which comprises the authentication apparatus of this invention, and is a top view which shows the Example at the time of forming an area sensor part on an insulating board | substrate at least. It is sectional drawing which shows one Example of the biometrics apparatus which comprises the said optical sensor apparatus. It is a graph for demonstrating the sensor element which has a sensitivity in a different wavelength band. FIG. 10 is a process diagram showing an embodiment of a method for manufacturing an authentication apparatus of the present invention, and is a diagram showing a series of processes in both FIG. 8 and FIG. 9. FIG. 10 is a process diagram showing an embodiment of a method for manufacturing an authentication device of the present invention, and is a diagram showing a series of processes in both FIG. 7 and FIG. 9. FIG. 9 is a process diagram showing an embodiment of a method for manufacturing an authentication apparatus according to the present invention, and both FIG. 7 and FIG. It is process drawing which shows the other Example of the manufacturing method of the authentication apparatus of this invention, and is a figure which shows a series of processes with FIG. It is process drawing which shows the other Example of the manufacturing method of the authentication apparatus of this invention, and is a figure which shows a series of processes with FIG. It is the top view which showed the Example in the case of mounting a biometrics authentication apparatus in an image display apparatus, and providing this image display apparatus with a personal authentication function. When the area sensor part is formed in the area of the pixel display part, it is a plan view showing an example of the arrangement of a plurality of types of sensors and pixels.

Explanation of symbols

  AS ... 1st sensor element, SB ... 2nd sensor element, TS ... Area sensor part, CNC ... Operation control circuit group, CNL ... Arithmetic processing circuit group, LCH ... Photoelectric conversion part, AML ... Electric charge Storage unit, WRT ... Reading unit, GL ... Gate line, RS ... Reset line, WT ... Reading line, FG ... Finger, MA ... First electromagnetic wave source, MB ... Second electromagnetic wave source, SSB: Sensor substrate, OCC: Transmission source control circuit, GRL1: Lower layer undercoat, GRL2: Upper layer underlayer, PS: Semiconductor film, RES: Photoresist film, GI: Gate insulating film, MTL ... Metal film, GT ... Gate electrode, CNL ... Wiring metal film, PAS1, PAS2, PAS3 '... Insulating protective film, nAS ... n-type semiconductor layer, iAS ... i-type semiconductor layer, pAS ... p Type semiconductor layer, TCN ... Bright conductive film, PNL: Image display device PNL with personal authentication function, AR: Image display unit, PRC: Peripheral circuit, PRC1: First peripheral circuit, PRC2: Second peripheral circuit

Claims (21)

  An area sensor unit in which a plurality of sensor elements for detecting electromagnetic waves are two-dimensionally arranged, an operation control circuit group of the area sensor unit, and an arithmetic process for calculating an output from the area sensor unit An optical sensor device comprising a circuit group, wherein the area sensor unit is constituted by two or more types of sensor element groups having different detection wavelength bands.   2. The optical sensor device according to claim 1, wherein the area sensor unit and a part of the arithmetic processing circuit group are formed on the same insulating substrate.   2. The optical sensor device according to claim 1, wherein sensor elements having two or more different detection wavelength bands have different film thicknesses of the photoelectric conversion units. 3.   2. The optical sensor device according to claim 1, wherein the sensor elements having two or more different detection wavelength bands are each composed of a PIN-type element whose current direction is perpendicular to the substrate surface, and is P-type, An optical sensor device characterized in that, among N-type regions, the thicknesses of regions on the incident light side are different from each other.   2. The optical sensor device according to claim 1, wherein the shape of the pixels of the various sensor elements is the same, and the arrangement pattern when viewed for each of the various sensors is one. .   2. The optical sensor device according to claim 1, wherein the pixel shape of each sensor element is the same, and there are at least two arrangement patterns when viewed for each sensor. .   2. The optical sensor device according to claim 1, wherein at least two types of sensor elements have different pixel shapes.   2. The optical sensor device according to claim 1, wherein at least one type of sensor element has two or more types of pixel shapes.   2. The optical sensor device according to claim 1, wherein at least one type of sensor element group is arranged in a line shape of 1 to 10 columns and N rows (N is an integer of 100 or more). Optical sensor device.   The sensor device according to claim 9, wherein the area sensor unit has a rectangular shape, and at least one type of sensor element group arranged in a line is arranged in a form along one side of the rectangle. An optical sensor device. A biometric authentication device comprising a source of electromagnetic waves for detection and a sensor device for detecting electromagnetic waves including information on characteristics of a living body,
The transmission source is constituted by two or more types of transmission sources having different wavelength bands,
The sensor device performs arithmetic processing on an area sensor unit in which a plurality of sensor elements for detecting electromagnetic waves are two-dimensionally arranged, an operation control circuit group of the area sensor unit, and an output from the area sensor unit A biometric authentication device, wherein the area sensor unit is configured by two or more sensor element groups having different detection wavelength bands.   12. The biometric authentication device according to claim 11, wherein two or more types of electromagnetic waves for detection having different wavelength bands both detect the same biometric feature.   The biometric authentication device according to claim 11, wherein two or more types of electromagnetic waves for detection having different wavelength bands respectively detect different biometric features.   12. The biometric authentication device according to claim 11, wherein the detection electromagnetic wave and the sensor element are of two types, and one set of the two types of detection electromagnetic wave and the sensor element has an intensity distribution in a wavelength band of 700 to 1000 nm. A biometric authentication device characterized by having a sensitivity distribution, and another set of electromagnetic waves for detection and sensor elements having an intensity distribution in a wavelength band of 500-700 nm. An image display device having a personal authentication function, wherein the personal authentication function includes a detection electromagnetic wave transmission source and a sensor device for detecting an electromagnetic wave including information on characteristics of a biological body. Because
The transmission source is constituted by two or more types of transmission sources having different wavelength bands,
The sensor device performs arithmetic processing on an area sensor unit in which a plurality of sensor elements for detecting electromagnetic waves are two-dimensionally arranged, an operation control circuit group of the area sensor unit, and an output from the area sensor unit An image display device comprising a biometric authentication device configured to include two or more types of sensor element groups having different detection wavelength bands.   16. The image display device according to claim 15, wherein the area sensor unit and the pixel unit are formed on the same insulating substrate.   The image display device according to claim 16, wherein at least a part of the circuit group is formed on the insulating substrate.   17. The image display device according to claim 16, wherein the pixel shape and size of each type of sensor element are the same as the pixel shape and size of each pixel.   17. The image display device according to claim 16, wherein the pixel shape and size of at least one sensor element are different from the pixel shape and size of each pixel.   17. The image display device according to claim 16, wherein at least one type of sensor element group is arranged in a line of 1 to 10 columns and N rows (N is an integer of 100 or more). Image display device.   21. The image display device according to claim 20, wherein at least one type of sensor element group arranged in a line is arranged in a form along one side forming the image display unit. Image display device.

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