JP2009133762A - Semiconductor device and its test method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which can perform a power-source current test by a semiconductor device as an object to be tested without using a current measuring unit of a tester. <P>SOLUTION: The semiconductor device comprises: a current/voltage conversion circuit (a resistor 103 and an amplifier 104) provided between a power-source terminal 108 and an internal circuit element; an analog/digital conversion circuit (ADC) 305; a built-in memory 304; and an arithmetic circuit 303. A test pattern is input into each input terminal of the semiconductor device 101 to operate the semiconductor device 101. The current/voltage conversion circuit converts the current passing between the power-source terminal 108 and the internal circuit element into voltage. The analog/digital conversion circuit 305 converts the output voltage of the current/voltage conversion circuit into a digital value. The built-in memory 304 stores the digital value. The arithmetic circuit 303 compares the digital value stored in the built-in memory 304 to a criterion value, and the comparison result is output from the output terminal of the semiconductor device 101. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a semiconductor device and a test method thereof, and in particular, belongs to a power supply current test system for a semiconductor device, and can arbitrarily set a test pattern regardless of whether the pattern is operating or not, such as software standby, IDDQ test, and sleep test. The present invention relates to a test mechanism that allows a semiconductor device itself to perform power supply current measurement, not a tester, and a power supply current test method.

  Conventionally, when performing a power supply current test of a semiconductor device, the following method has been employed.

  (1) The semiconductor device is operated with the test pattern, and the power source current is measured by the power source current measuring mechanism on the tester body side. The current measurement point is controlled by the tester separately from the test pattern, and the current is measured.

  (2) A resistance is inserted between the semiconductor device power supply and the tester power supply on the test jig, and a mechanism for measuring the potential difference between both ends of the resistance is provided to measure the power supply current when the semiconductor device operates. In order to realize the IDDQ test, a separate circuit may be necessary on the jig.

In addition, as a technique regarding such a power supply current test of an LSI, for example, techniques described in Patent Document 1 and Non-Patent Document 1 can be cited.
Japanese Patent Laid-Open No. 9-264921 “Chapter 9 Dynamic Current Test, Chapter 10 Standby Current Test” TDL Programming Guide (MANUAL No. 8350501-10), Advantest Corporation

  By the way, as a result of examination of the power source current test technique of the semiconductor device as described above by the present inventor, the following has been clarified.

  For example, since the measurement of the power supply current is not controlled by the test pattern but by the test program or the like, it takes time to measure the power supply current. Further, the power supply current measurement during the operation of the semiconductor device needs to be executed as an independent test. Furthermore, unlike the diagnosis of degeneracy / delay failure such as SCAN, AC-LBIST, and memory BIST, the power supply current test cannot be self-diagnosed by the semiconductor device itself based on the test standard.

  Accordingly, an object of the present invention is to provide a technique capable of performing a power supply current test by a semiconductor device to be tested itself without using a current measuring unit of a tester.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the embodiments disclosed in the present application, the outline of typical ones will be briefly described as follows.

  That is, a semiconductor device according to a typical embodiment includes a current / voltage conversion circuit, an analog / digital conversion circuit, a memory, and an arithmetic circuit provided between a power supply terminal or a ground terminal and an internal circuit element. Is. Then, a test pattern is input to each input terminal of the semiconductor device to operate the semiconductor device. The current / voltage conversion circuit converts a current flowing between the power supply terminal or the ground terminal and the internal circuit element into a voltage. The analog / digital conversion circuit converts the output voltage of the current / voltage conversion circuit into a digital value. A memory stores the digital value. The arithmetic circuit compares the digital value stored in the memory with the determination reference value. The comparison result is output from the output terminal of the semiconductor device. With this output, pass / fail judgment is performed. With this function, power supply current measurement can be realized in the form of execution of a function pattern without using a current measurement unit on the tester side.

  The effects obtained by the representative ones of the embodiments disclosed in the present application will be briefly described as follows.

  (1) Since the power supply current test of the semiconductor device can be performed simultaneously with the function test, the test using the tester's current measurement unit becomes unnecessary, and the test time is shortened.

  (2) When performing the IDDQ test, there is no need to add a measurement circuit on the jig.

  (3) The operation of the semiconductor device can be controlled based on the power supply current measurement value during operation.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  First, in order to make the features of the present invention easier to understand, the present invention will be described in comparison with the prerequisite technology of the present invention.

(Prerequisite technology)
FIG. 3 is a diagram showing a configuration of a semiconductor device and its test apparatus according to the premise technique of the present invention, and FIG. 4 is a flowchart showing a power source current test process of the semiconductor device in the test apparatus shown in FIG.

  First, an example of the configuration of the semiconductor device according to the base technology will be described with reference to FIG. The semiconductor device 301 according to the base technology is, for example, an LSI (abbreviation of Large Scale Integrated Circuit), and is formed on one semiconductor substrate by a well-known semiconductor manufacturing technology. The semiconductor device 301 includes, for example, an analog input control circuit 302, an arithmetic circuit 303, a built-in memory 304, an analog / digital conversion circuit (ADC) 305, switches (SW) 306 and 307, and the like. The arithmetic circuit 303, the built-in memory 304, and the analog / digital conversion circuit 305 are connected to an internal bus. Further, the semiconductor device 301 has a plurality of analog input terminals (analog inputs 0 to N), one analog input is selected by the analog input control circuit 302 and the switches 306 and 307, and the analog input is input from the analog input terminal. The signal is converted into digital data by the analog / digital conversion circuit 305.

  Although not shown in FIG. 3, the semiconductor device 301 includes a large number of internal circuit elements (such as logic circuits), and power is supplied to each internal circuit element from a power supply terminal 308 of the semiconductor device 301. Note that the reference power source of the analog / digital conversion circuit 305 is also omitted.

  Next, with reference to FIG. 3 and FIG. 4, a power source current test method for the semiconductor device 301 will be described. In a semiconductor test apparatus 309 such as a tester, when performing a power supply current test of the semiconductor device 301, an ammeter 310 and a power supply 311 are connected to the power supply terminal 308 of the semiconductor device 301. Then, a test pattern is input from the semiconductor test apparatus 309 to each input terminal of the semiconductor device 301.

  In FIG. 4, step S401 and step S405 are processes performed with a test pattern. Steps S402 to S404 are processes performed on the semiconductor test apparatus 309 (tester body) side.

  First, in step S401, a test pattern is input to each input terminal of the semiconductor device 301 to execute a current measurement pattern. Next, in step S <b> 402, current measurement is performed by the semiconductor test apparatus 309 (tester) using the ammeter 310. Next, in step S403, the current value is read. Next, in step S404, the read current value is determined. Next, in step S405, a current measurement pattern stop process is performed.

  As described above, the semiconductor device 301 is operated with the test pattern, and the power source current of the semiconductor device 301 is measured by the power source current measuring mechanism on the semiconductor test device 309 side.

(Embodiment)
FIG. 1 is a diagram showing a configuration of a semiconductor device and a test apparatus thereof according to an embodiment of the present invention, and FIG. 2 is a flowchart showing a power source current test process of the semiconductor device in the test apparatus shown in FIG.

  First, an example of the configuration of the semiconductor device according to the present embodiment will be described with reference to FIG. The semiconductor device 101 of the present embodiment is, for example, an LSI (abbreviation for Large Scale Integrated Circuit), and is formed on a single semiconductor substrate by a known semiconductor manufacturing technique. The semiconductor device 101 is obtained by adding a power supply current measuring circuit 102 to the semiconductor device 301 according to the above-described prerequisite technology. The power supply current measuring circuit 102 includes, for example, a resistor 103 having a resistance value of about several ohms, an amplifier 104, switches (SW) 105, 106, and 107.

  The power supply terminal 108 of the semiconductor device 101 is connected to one terminal of the switches 105 and 106 of the power supply current measuring circuit 102. The other terminal of the switch 105 is connected to one terminal of the resistor 103 and one input terminal of the amplifier 104. The other terminal of the resistor 103 is connected to the other input terminal of the amplifier 104. The resistor 103 and the amplifier 104 constitute a current / voltage conversion circuit that converts a current flowing between the power supply terminal 108 and the internal circuit element into a voltage. The output of the amplifier 104 is connected to one terminal of the switch 107. The other terminal of the switch 107 is connected to an input terminal of an analog / digital conversion circuit (ADC) 305. The control terminal of the switch 107 is connected to the analog input control circuit 302, and the analog input control circuit 302 controls the short circuit / cutoff of the switch 107. The control terminal of the switch 105 is connected to the current measurement path selection terminal of the semiconductor device 101 via the inverter, and the control terminal of the switch 106 is directly connected to the switch 105 exclusively by the current measurement path selection terminal. 106 are controlled. When the switch 105 is short-circuited, the power supply current measuring circuit 102 becomes effective.

  Although not shown in FIG. 1, there are a large number of internal circuit elements (such as logic circuits) in the semiconductor device 101, and power is supplied to each internal circuit element from the power supply terminal 108 of the semiconductor device 101. The other terminal of the switch 106 is connected to each internal circuit element, and when the switch 106 side is selected by the current measurement path selection terminal, power is supplied to each internal circuit element via the switch 106. The other terminal of the resistor 103 is connected to each internal circuit element. When the switch 105 side is selected by the current measurement path selection terminal, power is supplied to each internal circuit element via the switch 105 and the resistor 103. Is done.

  That is, a resistor 103 having a low resistance value is sandwiched between a power source side or a ground (GND) side of an internal circuit element (CMOS element or the like) on the semiconductor device 101, and current measurement is performed based on a voltage difference between both ends of the resistor 103. A power supply current measuring circuit 102 is provided.

  The current determination reference value is read in advance from a tester or the like into the built-in memory 304 (or register or the like). The test pattern is executed after enabling the power supply current measurement circuit 102 with the test pattern, and the data measured from the power supply current measurement circuit 102 is transferred to the built-in memory 304. Then, the arithmetic circuit 303 compares the current determination reference value with the measurement data, and outputs the result to the external terminal of the semiconductor device 101. With this output, the pass / fail judgment of the semiconductor device is performed. With this function, current measurement can be realized in the form of execution of a function pattern without using a current measurement unit on the tester side.

  Next, with reference to FIG. 1 and FIG. 2, a power source current test method for the semiconductor device 101 will be described. In FIG. 2, steps S201 to S206 are processes performed inside the semiconductor device 101 by the test pattern.

  Regarding the path between the power supply terminal of the semiconductor device 101 and the power supply node of the internal circuit element (CMOS element or the like), 2 of current path A (connected through the switch 106) and current path B (via switch 105 and the resistor 103 in series) Establish a route. It is assumed that the current paths A and B can be exclusively selected by the switches 105 and 106. When the power supply current is not measured, the current path A is validated.

  When measuring the power supply current of the semiconductor device 101, the power supply 111 is connected to the power supply terminal 108 of the semiconductor device 101 in the semiconductor test device 109 such as a tester. Then, a test pattern is input from the semiconductor test device 109 to each input terminal of the semiconductor device 101.

  First, in step S201, the current path B is validated. That is, the switch 105 is short-circuited by the current measurement path selection terminal 112 of the semiconductor device 101 to enable the power supply current measurement circuit 102.

  Next, in step S202, the test determination reference value is written into the built-in memory 304 from the outside of the semiconductor device 101. Alternatively, a register or the like that can refer to the determination reference value equivalent is mounted on the semiconductor device 101.

  Next, in step S203, an operation for current measurement is executed according to the test pattern, and the current of the semiconductor device 101 is measured by the resistor 103, the amplifier 104, the analog / digital conversion circuit 305, and the like. At that time, the switch 107 between the amplifier 104 and the analog / digital conversion circuit 305 is short-circuited. In addition, the current / measurement timing is instructed to the analog / digital conversion circuit 305.

  In step S204, the current measurement data of the digital value converted data output from the analog / digital conversion circuit 305 is written into the built-in memory 304.

  Next, in step S205, the current measurement data and the determination reference value written in the built-in memory 304 are read out and compared by the arithmetic circuit 303 to perform determination processing. Alternatively, a determination process is performed by comparing with data read from the analog / digital conversion circuit 305 based on a register or the like that can refer to the determination reference value.

  Finally, in step S206, the determination result compared by the arithmetic circuit 303 is output from the output terminal of the semiconductor device (LSI) 101. When used for switching the operation of the semiconductor device 101, the operation of the semiconductor device is controlled based on the determination result. For example, in order to prevent thermal runaway due to an excessive power supply current, when the measured power supply current exceeds a determination reference value, a process of switching to a standby mode or the like is performed.

  Therefore, according to the semiconductor device and the test method thereof according to the present embodiment, it is possible to cause the semiconductor device itself to measure the power supply current without increasing the chip size only by adding the small-scale power supply current measurement circuit 102. be able to.

  In addition, since the power supply current test of the semiconductor device can be performed simultaneously with the function test, the test using the tester current measurement unit is not required, and the test time is shortened. Further, when performing the IDDQ test, there is no need to add a measurement circuit on the jig. In addition, the operation of the semiconductor device can be controlled based on the power supply current measurement value during operation.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the invention is not limited to the embodiment, and various modifications can be made without departing from the scope of the invention. Needless to say.

  The present invention is particularly effective for a semiconductor device equipped with an analog / digital conversion circuit. This is because an existing analog / digital conversion circuit can be used for power supply current measurement in a semiconductor device, and the increase in chip area can be suppressed by diverting the circuit.

It is a figure which shows the structure of the semiconductor device by one embodiment of this invention, and its test device. 2 is a flowchart showing a process of a power supply current test for a semiconductor device in the test apparatus shown in FIG. It is a figure which shows the structure of the semiconductor device by the premise technique of this invention, and its test device. 4 is a flowchart showing a power source current test process of a semiconductor device in the test apparatus shown in FIG. 3.

Explanation of symbols

101, 301 Semiconductor device (LSI)
102 power supply current measuring circuit 103 resistor 104 amplifier 105, 106, 107, 306, 307 switch (SW)
108, 308 Power supply terminals 109, 309 Semiconductor test equipment 111, 311 Power supply 112 Current measurement path selection terminal 302 Analog input control circuit 303 Arithmetic circuit 304 Built-in memory 305 Analog / digital conversion circuit (ADC)
310 Ammeter

Claims (5)

A current / voltage conversion circuit which is provided between a power supply terminal or a ground terminal and an internal circuit element and converts a current flowing between the power supply terminal or the ground terminal and the internal circuit element into a voltage;
An analog / digital conversion circuit for converting an output voltage of the current / voltage conversion circuit into a digital value;
A memory for storing a digital value of an output voltage of the current / voltage conversion circuit converted by the analog / digital conversion circuit;
A semiconductor device comprising: an arithmetic circuit that compares a digital value of an output voltage of the current / voltage conversion circuit stored in the memory with a determination reference value. The semiconductor device according to claim 1,
The current / voltage conversion circuit includes:
A resistance element provided between the power supply terminal or ground terminal and the internal circuit element;
An amplifier for amplifying and outputting a voltage between both terminals of the resistance element; The semiconductor device according to claim 1 or 2,
The semiconductor device, wherein the determination reference value is stored in the memory. The semiconductor device according to any one of claims 1 to 3,
A semiconductor device having a function of controlling operation of the semiconductor device based on a comparison result of the arithmetic circuit. A test method for the semiconductor device according to claim 1,
A test pattern is input to each input terminal of the semiconductor device,
Based on the test pattern, the current / voltage conversion circuit, the analog / digital conversion circuit, the memory, and the arithmetic circuit operate,
The current / voltage conversion circuit converts a current flowing between the power supply terminal or the ground terminal and the internal circuit element into a voltage;
The analog / digital conversion circuit converts the output voltage of the current / voltage conversion circuit into a digital value;
The memory stores a digital value of an output voltage of the current / voltage conversion circuit converted by the analog / digital conversion circuit;
The arithmetic circuit compares the digital value of the output voltage of the current / voltage conversion circuit stored in the memory with a criterion value,
A test method for a semiconductor device, wherein a comparison result by the arithmetic circuit is output from an output terminal of the semiconductor device.

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