Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
  • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
  • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
  • G01N27/20—Investigating the presence of flaws
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
  • G01N29/04—Analysing solids
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/0095—Semiconductive materials
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L22/00—Testing or measuring during manufacture or treatment; Reliability measurements, i.e. testing of parts without further processing to modify the parts as such; Structural arrangements therefor
  • H01L22/20—Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
  • H01L22/24—Optical enhancement of defects or not directly visible states, e.g. selective electrolytic deposition, bubbles in liquids, light emission, colour change
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2291/00—Indexing codes associated with group G01N29/00
  • G01N2291/02—Indexing codes associated with the analysed material
  • G01N2291/028—Material parameters
  • G01N2291/02863—Electric or magnetic parameters

Definitions

• the invention relates to a method for detecting features of the spatial structure of an electrically conductive crystal, in particular a semiconductor, and an apparatus for carrying out the method.
• Structural features of crystal lattices can be examined and recorded in various ways.
• An obvious method is to look directly at the structure, i.e. the examination with the electron microscope.
• Another known method is X-ray structure analysis. For all known methods, very complex and therefore expensive equipment is required, which is only really justified if complex investigations have to be carried out.
• the invention has for its object to provide a method with which features of crystal structures can be detected in a very simple manner and without complex equipment.
• this object is achieved in that a measuring current is supplied to the crystal and a measurement of the charge distribution is carried out at a point on the crystal which is different from the current input and from which
• CONFIRMATION COPY Relationship between the measured charge distribution and a standard distribution information about the spatial structure can be obtained.
• Figure 1 is a schematic representation of the principle of the invention.
• Fig. 2 is a schematic representation of an embodiment of the invention;
• Fig. 3 is a schematic representation of an embodiment of a practical application of the invention;
• Fig. 4 shows an alternative to the embodiment according to
• FIGS. 5 to 7, further alternatives to FIG. 4; 8 shows a chip modified for use in accordance with the invention and FIGS. 9 and 10 versions of key chip card versions.
• FIG. 1 shows a crystal 1, which schematically represents a section of a semiconductor layer, as is known, for example, in semiconductor components
• Chips occur.
• the underside of the crystal is provided with individual, electrically separated electrodes 3, which are connected as current outputs or sinks.
• a full-surface electrode 4 is arranged on the top, which serves as a current input or source.
• the current flow in the crystal is such that electrons 5 migrate from the electrode 4 through the crystal to the sinks 3. In this way, they can be Structure of the crystal are more or less distracted.
• the arrows 7-9 show different electron paths. On path 7, an electron that enters the crystal at the source reaches the shortest path to the depression opposite the point of entry.
• the electrons are deflected and on a path 8 deviating from the straight path, they arrive at a sink other than that exactly opposite the point of entry.
• the effect of the perturbation on an electron can be so strong that it does not reach a depression on the other side of the crystal at all on a considerably deflected path 9.
• the source electrode 4 on the input side does not have to be formed over the entire surface, but can also consist of several individual electrodes. Both the source electrodes and the sink electrodes can be matrix-like or application-specific, e.g. for coding purposes.
• the impurities 6 in the crystal can be of different types, for example faults present in the crystal lattice, such as impurity atoms, lattice construction errors, or changes in the crystal lattice caused by external influences, such as mechanical or acoustic vibrations etc., e.g. the transitions from vibration nodes to vibrating material.
• the crystal can be used as a sensor for disturbances due to external influences.
• This is done in such a way that the deviations of a crystal with a real, individual lattice structure are compared with the scattering properties of a similar crystal, which, however, has an ideal, scatter-free inherent lattice structure and therefore serves as a standard for comparison.
• the measurement difference between the two accordingly quantifies the individuality of the real crystal under given external conditions.
• This measurement difference is stored as a reference for initializing this real crystal for future measurements, for example in the crystal itself if it is a semiconductor chip with storage options.
• the stored parameters can be used in this way for subsequent measurements of crystal lattice disturbances due to external influences in order to eliminate or balance the individual crystal properties which burden the measurement result.
• the measurement of the charge distribution at the sinks can be done in different ways.
• the sources can be designed as capacitors or transistors etc. for a subsequent electrical scanning.
• FIG. 2 A u f a substrate 18 of semi-insulating material is a layer of conductive material 17 is applied. A series of field effect transistors is formed in this conductive substrate, consisting of a source 10 ', a plurality of sinks 12 and a gate 16. The source 10' is provided with a source contact 11, and the sinks 12 are provided with sink contacts 13 for connection to the operating potential . The gate 16 is also provided with a gate contact 19.
• charge carriers 14 penetrate the crystal lattice structure in the region of the conductive channel 15.
• the individual sinks receive different characteristic potentials, which in their entirety form an evaluable and representative charge pattern across the crystal.
• the potentials of the sinks are measured with an evaluation circuit 20 and processed to form a distribution that maps the properties of the lattice structure.
• the crystalline substrate contains a larger number of, for example, 64 sinks instead of the three shown.
• the individual field effect transistors can be packed and contacted very densely.
• Ultrasonic waves that have been reflected or scattered from a specific structure carry information about this structure in the form of interference patterns. If a crystal is excited to vibrate with such ultrasonic waves, the information is transferred to the periodic changes in the lattice structure of the crystal. In other words, the temporary disturbances in the crystal are an image of the structure reflecting or backscattering the ultrasonic waves. Thus, with the crystal as a sensor, the information about the structure reflecting the ultrasonic waves is recorded directly at the field-effect transistors that are read out.
• FIG. 3 shows the ultrasound scanning of the epithelial structure of a finger and the detection of the information contained in the backscattered or reflected ultrasound waves with the semiconductor component contained on a so-called chip card 37.
• the finger 25 with its fingertip becomes conscious and briefly pressed on the adaptation surface 36 of the chip card 37 responsible for the biometric test.
• FIG. 3 corresponds in part to the configuration known from DE-A-4222387, but with the essential difference that the interfering ultrasonic waves are not scanned with light or other predetermined electromagnetic waves, but rather that measuring currents in the sense of the method according to the invention and sensor crystal layer 28 arranged in the device according to the invention, these measuring currents are initially excited to electromagnetic vibrations due to the periodic arrangement of the atomic trunks and their charge potentials in the crystal lattice, and are also temporarily deflected and scattered due to the additional physical measurement variables currently acting on the sensor crystal layer 28.
• Ultrasonic waves 24 are generated by the ultrasonic transducer 23 and through a device body and an adjacent adapter plate 37 'provided with a sensor crystal layer 28, which can also be designed as a chip card Epithelial structure 26 in the finger 25 sent as a biometric test specimen.
• the backscattered ultrasound waves 27 pass through the adapter plate 37 ', optionally in the form of a chip card, into the sensor crystal layer 28 and are detected there in the manner described.
• the sensor crystal layer 28 is shown separately next to the device body 22 in FIG. 3.
• a current is introduced into the sensor crystal layer 28 from a controlled current source 10
• the sinks 29 are connected to a measuring and amplifying unit 30 for the lower charges, which in turn is connected to an interface 31 for the measurement value acquisition. From there, the measured value information is sent to evaluation electronics 32 and from its output to a crypto processor 33 for data coding and an interface module 34 for networking.
• the evaluation circuit also contains an ultrasound transmitter 35, which is connected to the ultrasound transducer 23 and controls its radiation.
• this arrangement is preferably divided into a stationary and a mobile functional unit, the stationary functional unit containing the control electronics for the ultrasound generation and the ultrasound transducer and the device body, while the evaluation electronics and the adapter plate with the sensor crystal are in the mobile functional part, eg the chip of a chip card or smart card.
• the stationary functional unit containing the control electronics for the ultrasound generation and the ultrasound transducer and the device body, while the evaluation electronics and the adapter plate with the sensor crystal are in the mobile functional part, eg the chip of a chip card or smart card.
• Such arrangements are required, for example, for systems for biometrically supported person identification or verification in connection with the authentication of the chip of the corresponding chip card as its legitimation.
• the devices shown in Figs. 4-6 are various variations of other embodiments of smart card readers in which the present invention is used. With these devices, as I said, for the first time a physical verification, ie authentication of chip cards, is possible, which meets all requirements regarding security against counterfeiting and misuse and data protection.
• Smart cards the chip of which is equipped with a microprocessor system, have recently been called "smart cards" internationally. Due to the existing, high manipulative threat potential against smart cards, this area is likely to become a main area of application for the technology according to the invention. Further areas of application are personal computers, e.g. Enter keys or the PC mouce, cell phones, keys for locking systems, automobiles, keys for TV sets and much more.
• a station in which a transaction for example a cash withdrawal, is carried out by means of a chip card 37
• an ultrasound transmitter 23 below the card support surface 22 which emits ultrasound waves 24 upwards.
• the ultrasound waves penetrate the card and a finger passed over the card (finger scan) or a finger 25 resting on the card, which the cardholder places on a predetermined area on the card located in the station.
• Ultrasound is reflected or backscattered on the epithelium structure 26 in the epidernis of the fingertip of the finger 25.
• the backscattered wave component arrives again in the chip card 37 and there to the chip with the sensor crystal layer 28 arranged in the card.
• the chip of a chip card 37 is one of the chips usually used in chip cards with the functions required for the intended transactions, which is additionally provided with the sensors in the form of a matrix of field effect transistors required for the ultrasound detection of the method according to the invention.
• the sensors in the form of a matrix of field effect transistors required for the ultrasound detection of the method according to the invention.
• a number of unused transistors on the common chips that can be used for the present purpose. Otherwise, a commercially available chip would have to be slightly modified in order to implement a suitable transistor matrix.
• FIG. 8 A correspondingly modified chip is shown in FIG. 8.
• the unchanged application-specific circuit 43 is located on a conventional semiconductor chip 42.
• the receiving sensors 44 for ultrasound and the evaluation circuit elements 45 for processing the recorded information are arranged in the edge region of the chip that is not required for this purpose.
• switching elements 46 are provided for the position and clock frequency detection.
• the sensors in the chip detect the characteristic parameters of the backscattered ultrasound waves in the manner already described, which are combined in the chip to form a clear pattern that is representative of the individual epithelial structure and are compared with a stored pattern. If the two patterns are identical, the card user is clearly identified as the authorized owner. Only in this case does the chip release its functions for interaction with the station via a secure interface 34.
• the required electronic functions, which must run in the circuit on the chip, in order to obtain the recognition pattern from the detection signals, which must be compared with a stored pattern in order to enable the functions to be identified, are the task of the chip design and can be determined by the relevant specialist can be easily realized in different ways. A detailed description of the circuit can therefore be omitted here.
• FIG. 4 shows the ultrasound scanning of the epithelium structure 26 in the fingertip of the epidernis of the test specimen 25 and the detection of the information contained in the reflected ultrasound waves on the basis of a test arrangement designed as a scanner, over which the finger 25 must be moved in a predetermined direction 40 for testing.
• reception sensors on the chip integrated in the card, they can, as shown in FIG. 5, also be arranged in the station, possibly also as part of a microprocessor chip.
• the pattern required to identify the user is then compared with a pattern stored on the card chip and transmitted to the station via the interface when in use.
• the ultrasound transmitter in the station, it can also be arranged on the card, as shown in FIGS. 6 and 7.
• the sensor arrangement is also integrated in the card chip, while in the arrangement shown in FIG. 7 the sensor part is located in the station.
• the authorization check for chip cards in which it is important to verify that the respective user of the card is also its authorized holder, who then has access to the functions at any station, access to only one is possible with an electronic key only or only to a certain limited number of protected areas.
• a chip built into the key enables or creates the key function or the combination that matches the lock. The lock can only be opened with this key, which has been made suitable by the authorization determined.
• FIG. 9 there is a chip 49 with the stored locking code (crypto chip) and an integrated ultrasound receiver 50 on a key card 48.
• an ultrasound transmitter 51 is arranged on the card.
• the ultrasound transmitter 51 is not on the card 48 but in the station 52.

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• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Pathology (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Manufacturing & Machinery (AREA)
• Computer Hardware Design (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Power Engineering (AREA)
• Acoustics & Sound (AREA)
• Medicinal Chemistry (AREA)
• Food Science & Technology (AREA)
• Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
• Ultra Sonic Daignosis Equipment (AREA)
• Testing Or Measuring Of Semiconductors Or The Like (AREA)
• Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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ID=4234756

Family Applications (1)

Country Status (6)

Cited By (2)

Citations (6)

• 1999
  • 1999-12-15 CA CA002355144A patent/CA2355144A1/en not_active Abandoned
  • 1999-12-15 EP EP99959623A patent/EP1149283A1/de not_active Withdrawn
  • 1999-12-15 JP JP2000588595A patent/JP2002532714A/ja active Pending
  • 1999-12-15 KR KR1020017007528A patent/KR20010101248A/ko not_active Application Discontinuation
  • 1999-12-15 AU AU16750/00A patent/AU1675000A/en not_active Abandoned
  • 1999-12-15 WO PCT/IB1999/002047 patent/WO2000036406A1/de not_active Application Discontinuation

Patent Citations (6)

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