JP2008089484A - Semiconductor inspection mechanism, and inspection method of semiconductor integrated circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor inspection mechanism capable of accurately measuring the conversion characteristic of a D/A conversion circuit mounted on a semiconductor integrated circuit using a device of a voltage resolution lower than that of a measured D/A conversion circuit. <P>SOLUTION: The differential voltage obtained by subtracting supplied voltage of a voltage source 4 from the output voltage of the measured D/A conversion circuit 2 with a subtracting circuit 5 is measured by a voltage measurement device 6. The supplied voltage equal to the voltage occurring dependently on the state of upper level n bits in the measured D/A conversion circuit 2 is output from the voltage source 4. Only voltage of a small amplitude occurring dependently on the state of lower level bits in the measured D/A conversion circuit 2 is provided to the voltage measurement device 6. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a semiconductor inspection mechanism for inspecting a semiconductor integrated circuit including a D / A conversion circuit and an A / D conversion circuit, and a semiconductor integrated circuit inspection method.

  Conventionally, as a method for inspecting the D / A conversion characteristics of a D / A conversion circuit mounted on a semiconductor integrated circuit, the output voltage of the D / A conversion circuit to be measured is measured by a voltage measurement device built in the semiconductor inspection device. There have been proposed a method and a method of measuring the output voltage of the D / A converter circuit to be measured based on the converted digital code by supplying the output voltage of the D / A converter circuit to be measured to the A / D converter circuit. Also, the output voltage of the D / A conversion circuit to be measured is supplied to the A / D conversion circuit, and the digital code input to the D / A conversion circuit to be measured matches the digital code output from the A / D conversion circuit. A method for inspecting a D / A conversion circuit by making a determination with a comparison circuit has also been proposed (see, for example, Patent Document 1).

  On the other hand, conventionally, as an inspection method of A / D conversion characteristics of an A / D conversion circuit mounted on a semiconductor integrated circuit, a stepped voltage or a sinusoidal waveform that satisfies the maximum input voltage amplitude of the A / D conversion circuit to be measured is used. There has been proposed a method of inspecting A / D conversion characteristics by applying a voltage to a measured A / D conversion circuit and recording a digital code output from the measured A / D conversion circuit with a semiconductor inspection apparatus.

  However, in order to inspect the D / A conversion circuit and the A / D conversion circuit with a reasonable accuracy by the conventional method described above, the voltage resolution of the apparatus involved in the inspection is determined by the D / A conversion circuit to be measured or the A to be measured. It must be higher than the / D conversion circuit. For example, the D / A conversion characteristic of the D / A conversion circuit to be measured having a voltage resolution of 10 bits cannot be inspected with high accuracy by a voltage measuring device having a voltage resolution of 8 bits.

For this reason, conventionally, as the resolution of the D / A conversion circuit and the A / D conversion circuit mounted on the semiconductor integrated circuit is increased, a higher-resolution semiconductor inspection apparatus must be employed, which increases the inspection cost. It was a factor.
Japanese Patent Laid-Open No. 2-8760

  In view of the above problems, the present invention controls the supply voltage of the voltage source in accordance with the state of the digital code applied to the D / A converter circuit to be measured, and the output voltage of the D / A converter circuit to be measured and the voltage source By taking the difference from the supply voltage and measuring the difference voltage, the D / A conversion characteristic of the D / A conversion circuit mounted on the semiconductor integrated circuit can be reduced with a device having a lower voltage resolution than the D / A conversion circuit. It is an object of the present invention to provide a semiconductor inspection mechanism and a semiconductor integrated circuit inspection method that can be used with high accuracy.

  Further, in view of the above problems, the present invention generates an input voltage to the A / D conversion circuit to be measured using two voltage sources, thereby enabling A of the A / D conversion circuit mounted on the semiconductor integrated circuit. It is an object of the present invention to provide a semiconductor inspection mechanism and a semiconductor integrated circuit inspection method capable of inspecting the / D conversion characteristics with high accuracy using a device having a lower voltage resolution than the A / D conversion circuit.

  According to a first aspect of the present invention, there is provided a semiconductor inspection mechanism including a voltage source, a control unit for controlling a supply voltage of the voltage source in accordance with a state of a digital code supplied to the D / A conversion circuit to be measured, and the D to be measured. A subtractor that takes the difference between the voltage output from the / A converter circuit and the supply voltage of the voltage source, and a measuring unit that measures the output voltage of the subtractor.

  The semiconductor inspection mechanism according to a second aspect of the present invention is the semiconductor inspection mechanism according to the first aspect, wherein the control unit is configured such that the upper n (n is a positive value) of the digital code in the D / A conversion circuit to be measured. The supply voltage equivalent to the voltage generated depending on the bit state is output from the voltage source.

  A semiconductor inspection mechanism according to claim 3 of the present invention is the semiconductor inspection mechanism according to claim 1, wherein the voltage source is a D / A conversion circuit for a voltage source, and the control The unit supplies a part of the digital code to be supplied to the D / A conversion circuit to be measured to the D / A conversion circuit for voltage source.

  According to a fourth aspect of the present invention, there is provided a semiconductor inspection mechanism according to any one of the first to third aspects, wherein the supply voltage of the voltage source is added to the voltage value measured by the measurement unit. And an arithmetic unit for obtaining a D / A conversion characteristic of the D / A conversion circuit to be measured.

  The semiconductor inspection mechanism according to claim 5 of the present invention adds the first and second voltage sources and the supply voltages of the first and second voltage sources to the A / D conversion circuit to be measured. An addition unit that generates a voltage to be applied, and a digital code determination unit that determines a logical value of a digital code output from the measured A / D conversion circuit.

  The semiconductor inspection mechanism according to claim 6 of the present invention is the semiconductor inspection mechanism according to claim 5, wherein the first voltage source has a voltage having an amplitude corresponding to the voltage resolution of the second voltage source. It is characterized by generating.

  A semiconductor inspection mechanism according to claim 7 of the present invention is the semiconductor inspection mechanism according to claim 5 or 6, further comprising: an amplitude of a voltage output from the first voltage source; A comparison unit that compares the minimum fluctuation range of the voltage output from the second voltage source is provided.

  A semiconductor integrated circuit inspection method according to claim 8 of the present invention inspects a semiconductor integrated circuit including a D / A conversion circuit using the semiconductor inspection mechanism according to any one of claims 1 to 4. In the inspection method, the control condition of the voltage source is adjusted in advance so that the output voltage of the D / A converter circuit to be measured when a predetermined digital code is given matches the supply voltage of the voltage source, When inspecting the semiconductor integrated circuit, the supply voltage of the voltage source is controlled using the control conditions adjusted in advance.

  According to a ninth aspect of the present invention, there is provided a semiconductor integrated circuit inspection method that inspects a semiconductor integrated circuit including an A / D conversion circuit using the semiconductor inspection mechanism according to any one of the fifth to seventh aspects. In the inspection method, the first and second voltage sources are controlled such that the amplitude of the voltage output from the first voltage source matches the minimum fluctuation range of the voltage output from the second voltage source. The condition is adjusted in advance, and when the semiconductor integrated circuit is inspected, the supply voltage of the first and second voltage sources is controlled using the previously adjusted control condition.

  According to the present invention, the D / A conversion characteristic of the D / A conversion circuit included in the semiconductor integrated circuit and the A / D conversion characteristic of the A / D conversion circuit are more improved than those of the D / A conversion circuit and the A / D conversion circuit. Inspection can be performed with high accuracy using an apparatus having a low voltage resolution.

  That is, in the inspection of the D / A conversion circuit, a small-amplitude voltage waveform obtained by removing the voltage fluctuation due to the state of the upper n bits from the output voltage of the D / A conversion circuit to be measured is measured, and the measurement result includes the upper n The D / A conversion characteristic of the D / A conversion circuit to be measured can be acquired by adding the voltage fluctuation due to the bits. In addition, the measurement unit need only be able to measure voltage fluctuations due to the state of the lower bits of the D / A converter circuit to be measured. Even if the voltage resolution of the measurement unit is less than the number of bits of the D / A converter circuit to be measured, The D / A conversion characteristics can be inspected with the same accuracy as when a voltage measuring device with a resolution is used.

  In the inspection of the A / D conversion circuit, a voltage having a small amplitude is generated from the first voltage source, a voltage having a large voltage step is generated from the second voltage source, and these are added to reduce the step. In addition, a voltage having a large amplitude can be generated and supplied to the A / D conversion circuit to be measured. Therefore, the voltage resolution required for the first and second voltage sources is reduced, and a high-resolution voltage source is used even when the voltage resolution of the voltage source is less than the number of bits of the A / D conversion circuit to be measured. The A / D conversion characteristics can be inspected with the same accuracy as the case.

(Embodiment 1)
FIG. 1 is a diagram showing a configuration of a semiconductor inspection apparatus (semiconductor inspection mechanism) in Embodiment 1 of the present invention, and shows an outline of a configuration relating to output measurement of a D / A conversion circuit included in a semiconductor integrated circuit to be inspected. Show.

  As shown in FIG. 1, the semiconductor inspection apparatus includes a signal generator 3, a voltage source 4, a subtraction circuit (subtraction unit) 5, and a voltage measurement device (measurement unit) 6. The output of the D / A conversion circuit (D / A conversion circuit to be measured) 2 included in the semiconductor integrated circuit (measured semiconductor integrated circuit) 1 is measured.

  The signal generator 3 outputs an input signal series (digital code) necessary for the inspection of the D / A conversion circuit 2 to be measured. In addition, the signal generator 3 has a function of a control unit that controls the supply voltage of the voltage source 4 in accordance with the state of each signal of the input signal series supplied to the D / A conversion circuit 2 to be measured. The voltage source 4 is configured to arbitrarily control the supply voltage.

  Specifically, the signal generator 3 supplies a supply voltage equivalent to the voltage generated depending on the state of the upper n bits (n is a positive integer) of the digital code in the D / A conversion circuit 2 to be measured. 4 is supplied with a control signal for output.

  For example, when the voltage resolution of the D / A conversion circuit 2 to be measured is 8 bits and the binary digital code is sequentially output from the signal generator 3 in ascending order from the zero code to the full code, the D / A conversion circuit 2 to be measured The voltage shown in FIG. 2 is output. At this time, the supply voltage equivalent to the voltage generated depending on the state of the upper 5 bits of the digital code in the D / A conversion circuit 2 to be measured is output from the voltage source 4. In this case, the waveform of the supply voltage of the voltage source 4 is a stepped waveform as shown in FIG. That is, in FIG. 3, for example, the supply voltage up to the first step corresponds to a digital code of “'00000000' to '00000111'”, and the voltage value is input to the D / A conversion circuit 2 to be measured. This is equivalent to the voltage value generated when the digital code is in the “00000000” state. The supply voltage of the first step corresponds to a digital code of “'00001000' to '000011111'”, and the digital value input to the D / A conversion circuit 2 to be measured is “00001000”. It is equivalent to the voltage value generated in the case of this state.

  The subtraction circuit 5 calculates the difference between the voltage output from the D / A conversion circuit 2 to be measured and the supply voltage of the voltage source 4. Here, the subtraction circuit 5 may be a differential amplifier. Moreover, you may use the differential voltage measuring apparatus which has a function of a subtracter as a voltage measuring apparatus not via the subtraction circuit 5. FIG. When the amplitude of the supply voltage of the voltage source 4 is too large or too small with respect to the output voltage amplitude of the D / A conversion circuit 2 to be measured, a voltage conversion function is provided between the voltage source 4 and the subtraction circuit 5. A circuit having: If the voltage amplitude measurable by the voltage measuring device 6 is too large or too small relative to the output voltage amplitude of the D / A conversion circuit 2 to be measured, the subtracting circuit 5 and the voltage measuring device 6 are not connected. A circuit having a voltage conversion function may be incorporated.

The voltage measuring device 6 measures the output voltage of the subtracting circuit 5. When the voltage resolution of the D / A conversion circuit 2 to be measured is a and a voltage equivalent to a voltage generated depending on the state of the upper n bits in the D / A conversion circuit 2 to be measured is supplied from the voltage source 4, subtraction is performed. The amplitude of the voltage output from the circuit 5 is 1/2 ^(an) of the output voltage amplitude of the D / A conversion circuit 2 to be measured. When the output of the subtracting circuit 5 is measured by the voltage measuring device 6 with m-bit voltage resolution, as a result, the output voltage of the D / A converter circuit 2 to be measured is measured with voltage resolution of “m + (a−n)” bits. The same measurement as when it is done.

  For example, the voltage resolution of the D / A conversion circuit 2 to be measured is 8 bits, and the voltage shown in FIG. 2 is output, which is generated depending on the state of the upper 5 bits in the D / A conversion circuit 2 to be measured. When the supply voltage equivalent to the voltage shown in FIG. 4 is output from the voltage source 4, the voltage shown in FIG. 4 is measured by the voltage measuring device 6, and compared with the case where the voltage shown in FIG. Voltage measurement with the same accuracy is possible with low voltage resolution.

  Further, although not shown in the figure, in the arithmetic unit provided in the semiconductor inspection apparatus, the value of the supply voltage of the voltage source 4 is added to the voltage value measured by the voltage measuring device 6 by calculation, and the D / A conversion circuit 2 to be measured By obtaining the D / A conversion characteristics, the semiconductor integrated circuit 1 to be measured can be inspected.

  As described above, according to the first embodiment, it is possible to obtain the D / A conversion characteristics of the D / A conversion circuit 2 to be measured with high accuracy using the low-resolution voltage measurement device. That is, a voltage waveform with a small amplitude obtained by removing the voltage fluctuation due to the state of the upper n bits from the output voltage of the D / A converter circuit 2 to be measured is added, and the voltage fluctuation due to the upper n bits is added to the measurement result. The D / A conversion characteristics of the D / A conversion circuit 2 to be measured can be acquired. The voltage measuring device 6 only needs to measure voltage fluctuations due to the state of the lower bits of the D / A conversion circuit 2 to be measured. The voltage resolution of the voltage measuring device 6 is equal to the number of bits of the D / A conversion circuit 2 to be measured. Even if not, the D / A conversion characteristics can be inspected with the same accuracy as when a high-resolution voltage measuring device is used.

  As the voltage source 4, a voltage source provided in an inspection board for electrically connecting the semiconductor inspection apparatus and the semiconductor integrated circuit 1 to be measured, or a voltage source provided in the semiconductor integrated circuit 1 to be measured may be used. According to this configuration, the output measurement of the D / A conversion circuit 2 to be measured can be realized by the inspection method in the first embodiment even when a semiconductor inspection apparatus that does not have the voltage source 4 capable of arbitrarily controlling the supply voltage is used. can do.

  Further, as the subtracting circuit 5, a subtracting circuit provided in an inspection board for electrically connecting the semiconductor inspection apparatus and the semiconductor integrated circuit 1 to be measured, or a subtracting circuit provided in the semiconductor integrated circuit 1 to be measured may be used. According to this configuration, even if a semiconductor inspection apparatus that does not have the subtracting circuit 5 is used, the output measurement of the D / A conversion circuit 2 to be measured can be realized by the inspection method in the first embodiment.

  Further, as the subtraction circuit 5 and the voltage measuring device 6, a differential input A / D conversion circuit provided in the semiconductor integrated circuit 1 to be measured and a digital code determination device provided in the semiconductor inspection device may be used. Specifically, one input terminal of the differential input A / D conversion circuit is connected to the output terminal of the D / A conversion circuit 2 to be measured, and the other input terminal is connected to the output terminal of the voltage source 4 to obtain the difference. The output terminal of the dynamic input A / D conversion circuit is connected to the digital code determination device, and the voltage output from the D / A conversion circuit 2 to be measured and the supply voltage of the voltage source 4 in the differential input A / D conversion circuit In the digital code determination device, the logical value of the digital code output from the differential input A / D conversion circuit is determined. Then, a calculation unit (not shown) provided in the semiconductor inspection apparatus measures a differential voltage between the output voltage of the D / A conversion circuit 2 to be measured and the supply voltage of the voltage source 4 based on the determination result. According to this configuration, the output measurement of the D / A conversion circuit 2 to be measured can be realized by the inspection method according to the first embodiment even if a semiconductor inspection apparatus that does not have the voltage measurement apparatus 6 is used.

  In addition, when zero is input to bits other than the upper n bits, if there is a difference between the voltage output from the D / A conversion circuit 2 to be measured and the voltage output from the voltage source 4, the D to be measured The D / A conversion characteristic of the / A conversion circuit 2 cannot be calculated correctly.

  Therefore, the control condition of the voltage source 4 in which the output voltage of the D / A conversion circuit 2 to be measured and the supply voltage of the voltage source 4 when a predetermined digital code is given is checked in advance, and the semiconductor integrated circuit 1 to be measured is When inspecting, the result is used for the inspection.

  Specifically, a digital code with bits other than the upper n bits set to zero is sequentially given to the D / A conversion circuit 2 to be measured so that the measurement result of the voltage measuring device 6 becomes 0 volt for each input. The control conditions of the voltage source 4 are adjusted in advance. Then, when inspecting the semiconductor integrated circuit 1 to be measured, the supply voltage of the voltage source 4 is controlled using the control conditions adjusted in advance. In this way, it is possible to prevent deterioration in output measurement accuracy of the D / A conversion circuit 2 to be measured.

(Embodiment 2)
FIG. 5 is a diagram showing the configuration of the semiconductor inspection apparatus (semiconductor inspection mechanism) in the second embodiment of the present invention, and shows an outline of the configuration relating to the output measurement of the D / A conversion circuit included in the semiconductor integrated circuit to be inspected. Show. However, the same members as those described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The semiconductor inspection apparatus is characterized in that a D / A conversion circuit (voltage source D / A conversion circuit 7) is used as the voltage source 4 described in the first embodiment. A part of the digital code input terminal of the voltage source D / A conversion circuit 7 is connected to a part of the digital code input terminal of the D / A conversion circuit 2 to be measured, and the signal generator (control unit) 3 Supplies a part of the input signal sequence (digital code) to be supplied to the D / A conversion circuit 2 to be measured to the D / A conversion circuit 7 for voltage source. The other digital code input terminal of the D / A conversion circuit 2 to be measured is grounded.

  Specifically, the upper n bits of the input signal series are shared between the D / A conversion circuit 2 to be measured and the D / A conversion circuit 7 for the voltage source, so that the voltage from the D / A conversion circuit 2 to be measured When a D / A conversion circuit having a low resolution and a maximum output voltage amplitude equivalent to the D / A conversion circuit 2 to be measured is used for the voltage source D / A conversion circuit 7, the voltage source 4 in the first embodiment is used. Similarly, the voltage source D / A conversion circuit 7 generates a supply voltage equivalent to the voltage generated in the D / A conversion circuit 2 to be measured depending on the state of the upper n bits of the digital code. With this configuration, the D / A conversion circuit to be measured and the D / A conversion circuit for voltage source can be controlled simultaneously, and the number of terminals required for the signal generator can be greatly reduced.

  The voltage source D / A conversion circuit 7 includes a D / A conversion circuit included in an inspection board for electrically connecting the semiconductor inspection apparatus and the semiconductor integrated circuit 1 to be measured, and the semiconductor integrated circuit 1 to be measured. A D / A conversion circuit may be used. According to this configuration, the output measurement of the D / A conversion circuit 2 to be measured can be realized by the inspection method according to the second embodiment even if a semiconductor inspection apparatus that does not have the voltage source D / A conversion circuit 7 is used. Can do.

  Further, when zero is input to bits other than the upper n bits, there is a difference between the voltage output from the D / A conversion circuit 2 to be measured and the voltage output from the voltage source D / A conversion circuit 7. If so, the D / A conversion characteristics of the D / A conversion circuit 2 to be measured cannot be calculated correctly.

  Therefore, the control of the voltage source D / A conversion circuit 7 in which the output voltage of the D / A conversion circuit 2 to be measured and the supply voltage of the voltage source D / A conversion circuit 7 coincide with each other when a predetermined digital code is given. When the conditions are checked in advance and the semiconductor integrated circuit 1 to be measured is inspected, an inspection is performed using the result.

  Specifically, a digital code with bits other than the upper n bits set to zero is sequentially given to the D / A conversion circuit 2 to be measured so that the measurement result of the voltage measuring device 6 becomes 0 volt for each input. Further, the value (control condition) of the reference voltage used for generating the voltage value output by the voltage source D / A conversion circuit 7 in accordance with the input digital code is adjusted in advance. Then, when inspecting the semiconductor integrated circuit 1 to be measured, the supply voltage of the voltage source D / A conversion circuit 7 is controlled using the control conditions adjusted in advance. In this way, it is possible to prevent deterioration in output measurement accuracy of the D / A conversion circuit 2 to be measured.

(Embodiment 3)
FIG. 6 is a diagram showing a configuration of a semiconductor inspection apparatus (semiconductor inspection mechanism) according to the third embodiment of the present invention. For the A / D conversion specific inspection of the A / D conversion circuit included in the semiconductor integrated circuit to be inspected. An outline of such a configuration is shown.

  As shown in FIG. 6, the semiconductor inspection apparatus includes a first power supply 13, a second power supply 14, an adder circuit (adder unit) 15, and a digital code determination device (digital code determination unit) 16. The A / D conversion specification of the A / D conversion circuit (measured A / D conversion circuit) 12 included in the semiconductor integrated circuit (measured semiconductor integrated circuit) 11 to be inspected is used.

  The first and second power supplies 13 and 14 can arbitrarily control the supply voltage, and are smaller than the maximum input voltage amplitude of the A / D conversion circuit 12 to be measured from the first voltage source 13. A voltage having an amplitude is generated, and a stepped voltage is generated from the second voltage source 14 with the amplitude of the voltage supplied from the first voltage source 13 as a minimum unit fluctuation range.

  The adder circuit 15 adds the voltages supplied from the first and second voltage sources 13 and 14 to generate a voltage to be supplied to the A / D conversion circuit 12 to be measured. The digital code determination device 16 determines the logical value of the digital code output from the A / D conversion circuit 12 to be measured.

  For example, when the input voltage shown in FIG. 2 is necessary to inspect the A / D conversion characteristic of the A / D conversion circuit 12 to be measured, the first voltage source 13 generates a voltage having a small amplitude shown in FIG. A voltage having a large voltage step shown in FIG. 3 is generated from the second voltage source 14 and added to generate a voltage having a small step and a large amplitude. At this time, the amplitude of the voltage shown in FIG. 4 and the minimum fluctuation range of the voltage shown in FIG.

  Here, the first voltage source 13 and the second voltage source 14 may use a D / A conversion circuit or an arbitrary waveform generator. Moreover, the combination of the voltage values generated from these two voltage sources is not limited to the above, and it is only necessary to obtain a desired input voltage necessary for the inspection as an addition result.

  When the voltage resolution of the first voltage source 13 is i bits and the voltage resolution of the second voltage source 14 is j bits, the voltage having an amplitude corresponding to the voltage resolution of the second voltage source 14 from the first voltage source 13 Is output from the second voltage source 14 and a voltage having an amplitude equivalent to the maximum input voltage amplitude of the A / D conversion circuit 12 to be measured is output, and these are added together to measure the voltage with a voltage resolution of i + j bits. An inspection voltage can be supplied to the A / D conversion circuit 12.

  As described above, the supply voltages of the first voltage source 13 and the second voltage source 14 are added by the adder circuit 15 to supply a voltage that satisfies the maximum input voltage amplitude of the A / D conversion circuit 12 to be measured. The A / D conversion characteristic of the measured A / D conversion circuit 12 can be obtained, and a voltage source having a higher voltage resolution is used by using a voltage source having a lower voltage resolution than the measured A / D conversion circuit. Inspection with the same accuracy as the case can be realized.

  However, when the amplitude of the voltage supplied from the first voltage source 13 and the fluctuation range of the minimum unit of the voltage supplied from the second voltage source 14 do not match, the voltage output from the adder circuit 15 does not have a desired waveform. .

  Therefore, the control conditions of the first and second voltage sources 13 and 14 in which the amplitude of the voltage supplied from the first voltage source 13 and the minimum unit of the fluctuation range of the voltage supplied from the second voltage source 14 coincide are set. When the semiconductor integrated circuit 11 to be measured is inspected in advance and inspected, the inspection is performed using the result.

  Specifically, the output terminal of the first voltage source 13 and the output terminal of the second voltage source 14 are respectively connected to the input terminals of a comparator (not shown) included in the semiconductor inspection apparatus, and the first The maximum voltage is output from the voltage source 13 and the voltage equal to the minimum unit of voltage fluctuation is output from the second voltage source 14. Then, based on the comparison result of the comparator, the control conditions of the first and second voltage sources 13 and 14 are set so that the output voltage of the first voltage source 13 and the output voltage of the second voltage source 14 match. Is adjusted in advance. Then, when inspecting the semiconductor integrated circuit 11 to be measured, the supply voltages of the first and second voltage sources 13 and 14 are controlled using the control conditions adjusted in advance. In this way, it is possible to prevent deterioration in inspection accuracy of the A / D conversion circuit 12 to be measured.

  As a comparator (comparator) for comparing the amplitude of the voltage output from the first voltage source 13 and the minimum fluctuation range of the voltage output from the second voltage source 14, the semiconductor inspection apparatus and the semiconductor to be measured A comparator provided in an inspection board that electrically connects the integrated circuit 11 or a comparator provided in the semiconductor integrated circuit 11 to be measured may be used. According to this configuration, the A / D conversion circuit 12 to be measured can be inspected by the inspection method in the third embodiment even using a semiconductor inspection apparatus that does not have a comparator.

  Further, as the adder circuit 15, an adder circuit provided in a test board for electrically connecting the semiconductor inspection apparatus and the semiconductor integrated circuit 11 to be measured, or an adder circuit provided in the semiconductor integrated circuit 11 to be measured may be used. According to this configuration, the A / D conversion circuit 12 to be measured can be inspected by the inspection method according to the third embodiment even if a semiconductor inspection apparatus that does not have the addition circuit 15 is used.

  Further, as the first and second voltage sources 13 and 14, a voltage source (including a D / A conversion circuit) included in an inspection board that electrically connects the semiconductor inspection apparatus and the semiconductor integrated circuit 11 to be measured, A voltage source (including a D / A conversion circuit) included in the semiconductor integrated circuit 11 to be measured may be used. According to this configuration, even if a semiconductor inspection apparatus that does not have a voltage source (including a D / A conversion circuit or the like) that can arbitrarily control the supply voltage is used, the A / D The D conversion circuit 12 can be inspected.

  According to the semiconductor inspection mechanism and the semiconductor integrated circuit inspection method of the present invention, the conversion characteristics of the D / A conversion circuit and the A / D conversion circuit included in the semiconductor integrated circuit are converted into the D / A conversion circuit and the A / D conversion circuit. Therefore, it is possible to inspect with high accuracy using a device having a lower voltage resolution than that, and it is useful for inspecting semiconductor products having high-resolution D / A conversion circuits and A / D conversion circuits.

The figure which shows the structure of the semiconductor inspection apparatus in Embodiment 1 of this invention. The figure which shows an example of the output voltage of the to-be-measured D / A converter circuit in Embodiment 1 or 2 of this invention, and the input voltage of the to-be-measured A / D converter circuit in Embodiment 3 of this invention Supply voltage of the voltage source in the first embodiment of the present invention, supply voltage of the D / A conversion circuit for the voltage source in the second embodiment of the present invention, and supply of the second voltage source in the third embodiment of the present invention Diagram showing an example of voltage The figure which shows an example of the output voltage of the subtraction circuit in Embodiment 1 or 2 of this invention, and the supply voltage of the 1st voltage source in Embodiment 3 of this invention The figure which shows the structure of the semiconductor inspection apparatus in Embodiment 2 of this invention. The figure which shows the structure of the semiconductor inspection apparatus in Embodiment 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 11 Semiconductor integrated circuit to be measured 2 D / A converter circuit to be measured 3 Signal generator 4 Voltage source 5 Subtractor circuit 6 Voltage measuring device 7 D / A converter circuit for voltage source 12 A / D converter circuit to be measured 13 1st Voltage source 14 Second voltage source 15 Adder circuit 16 Digital code determination device

Claims (9)

A voltage source;
A control unit for controlling the supply voltage of the voltage source in accordance with the state of the digital code applied to the D / A conversion circuit to be measured;
A subtractor that takes the difference between the voltage output from the D / A converter circuit to be measured and the supply voltage of the voltage source;
A measurement unit for measuring the output voltage of the subtraction unit;
Semiconductor inspection mechanism equipped with.   The controller causes the voltage source to output a supply voltage equivalent to a voltage generated depending on the state of upper n bits (n is a positive integer) of the digital code in the D / A converter circuit to be measured. The semiconductor inspection mechanism according to claim 1.   3. The semiconductor inspection mechanism according to claim 1, wherein the voltage source is a voltage source D / A conversion circuit, and the control unit provides a digital code to be supplied to the D / A conversion circuit to be measured. A part of the semiconductor inspection mechanism is provided to the voltage source D / A conversion circuit.   4. The semiconductor inspection mechanism according to claim 1, further comprising performing an operation of adding a value of a supply voltage of the voltage source to a voltage value measured by the measurement unit, and measuring the D / A to be measured. A semiconductor inspection mechanism comprising an arithmetic unit for obtaining D / A conversion characteristics of a conversion circuit. First and second voltage sources;
An adder for adding the supply voltages of the first and second voltage sources to generate a voltage to be supplied to the A / D converter circuit to be measured;
A digital code determination unit for determining a logical value of a digital code output from the measured A / D conversion circuit;
Semiconductor inspection mechanism equipped with.   6. The semiconductor inspection mechanism according to claim 5, wherein the first voltage source generates a voltage having an amplitude corresponding to a voltage resolution of the second voltage source.   7. The semiconductor inspection mechanism according to claim 5, further comprising: an amplitude of a voltage output from the first voltage source; and a minimum fluctuation range of a voltage output from the second voltage source. A semiconductor inspection mechanism comprising a comparison unit for comparing the two.   An inspection method for inspecting a semiconductor integrated circuit having a D / A conversion circuit using the semiconductor inspection mechanism according to claim 1, wherein a D to be measured when a predetermined digital code is given. The control conditions of the voltage source are adjusted in advance so that the output voltage of the A / A converter circuit and the supply voltage of the voltage source match, and when the semiconductor integrated circuit is inspected, the control conditions adjusted in advance are used. A method for inspecting a semiconductor integrated circuit, comprising controlling a supply voltage of the voltage source.   An inspection method for inspecting a semiconductor integrated circuit including an A / D conversion circuit using the semiconductor inspection mechanism according to claim 5, wherein the amplitude of the voltage output from the first voltage source When the semiconductor integrated circuit is inspected, the control conditions of the first and second voltage sources are adjusted in advance so that the minimum fluctuation range of the voltage output from the second voltage source matches. A method for inspecting a semiconductor integrated circuit, comprising: controlling supply voltages of the first and second voltage sources using control conditions adjusted in advance.

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