JP2597580B2 - Semiconductor measuring equipment - Google Patents

Description

The present invention relates to a semiconductor measuring device for measuring electrical characteristics of a semiconductor device such as a semiconductor integrated circuit and a semiconductor light-emitting device.

(Prior Art) A semiconductor device such as an IC (semiconductor integrated circuit) and an LED (semiconductor light emitting device) is subjected to measurement of various electrical characteristics after manufacturing, and is subjected to pass / fail classification or classification. Among such measurement items is DC parameter measurement. In this measurement, output voltages and currents are measured while various values of voltages and currents are applied to the semiconductor device to be measured, and a judgment is made based on the measured values.

FIG. 6 is a block diagram showing the configuration of a conventional measuring device for performing DC parameter measurement, and FIG. 7 is a timing chart when the measurement is performed by this device. That is, this device performs DC parameter measurement as follows. First, when the measurement is started, the measurement conditions in the test program are read from the CPU 11 and set in the relay matrix 12 and the analog measurement unit 13. As a result, the analog measuring unit 13 selects a required one of the plurality of program power supplies 15 under the control of the measurement timing controller 14, and outputs a voltage or current for measurement from the selected program power supply 15. In the relay matrix 12, the switches provided at each intersection and indicated by circles in the figure are selectively closed based on the above conditions.
As a result, the measurement voltage and current output from the program power supply 15 are supplied to an IC (hereinafter, referred to as DUT = Device Under Test) 16 as a semiconductor device to be measured via the relay matrix 12. In response to this input voltage and current, DU
The voltage and current output from T16 are once again in the relay matrix 1.
The power is supplied to the measurement power supply 17 in the analog measurement unit 13 via the second power supply 2. The voltage and current measured by the measurement power supply 17 are amplified by an amplifier (AMP) 18. After the elapse of the measurement time, the A / D converter 19 is started under the control of the measurement timing controller 14, and the output of the amplifier 18 is converted into digital data and supplied to the CPU 11. The CPU 11 makes a GO / NO-GO determination based on the digital data, and displays the result on the CRT display device 20. The period in FIG.
D1 and D2 are wait periods called on-delay and off-delay, respectively.

By the way, the circuit conditions for performing DC parameter measurement with the above-mentioned conventional device include the type of DUT, the voltage to be applied, the current conditions (program voltage, current range),
Measurement voltage, current conditions (measurement voltage, current range),
Measurement time (this measurement time refers to the time from when the program power supply and the measurement power supply are operated to when the A / D conversion is started). Of these, or
It can be uniquely determined by the measurement principle conditions of the DUT. However, regarding the measurement time, since the rise time of the power supply and the stabilization time of the circuit differ for each measurement device,
A decision by a professional technician is required. In other words, to determine this time, use a measuring instrument such as an oscilloscope to observe how long the voltage for measurement and the signal at the measurement terminal of the DUT have stabilized after the power is applied, Alternatively, data is collected for each measurement, and the data is determined based on the result of the data processing. In any of the above methods, a professional engineer and a long time are required to determine the measurement time.

(Problems to be Solved by the Invention) As described above, in order to determine the optimum measurement time in the conventional measuring device, a skilled technician is required, expensive various measuring instruments are required, To be able to fully use the DUT,
They are familiar with the configuration of the measurement device itself, the contents of the test program, the measurement principle, and the like. Conventionally, there is a problem that anyone cannot easily determine the optimum time and perform measurement. SUMMARY OF THE INVENTION It is an object of the present invention to provide a semiconductor measuring apparatus that can easily measure the electrical characteristics of a semiconductor device under optimum conditions in a short time.

[Structure of the Invention] (Means for Solving the Problems) A semiconductor measuring apparatus according to the present invention includes: an analog measuring unit that detects a signal corresponding to an electrical characteristic of a semiconductor device to be measured; An A / D conversion unit that sequentially converts the signal detected by the analog measurement unit into digital data at predetermined timings after the start, a data holding unit that holds the digital data converted by the A / D conversion unit,
Determining means for determining whether or not the electrical characteristics of the semiconductor device to be measured are good or not based on whether or not the value of the data held last by the data holding unit falls within a certain range; and A display unit for displaying the electrical characteristics of the semiconductor device under test with time based on the data held in the data holding unit after the end, and displaying the judgment result by the judging means.

(Operation) In the semiconductor measuring device according to the present invention, the signal detected by the analog measuring unit is sequentially converted into digital data at predetermined timings and held in the data holding unit. Then, based on the held data, the electrical characteristics of the semiconductor device to be measured are displayed with time.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a configuration when a semiconductor measuring device according to the present invention is applied to a DC parameter measuring device. In the figure, 11 is a CPU that controls the entire apparatus based on a predetermined test program, 12 is a relay matrix provided with a plurality of switches, 13 is an analog measurement unit,
16 is a DUT and 20 is a CRT display.

The analog measurement section 13 is provided with a measurement timing controller 14, a plurality of program power supplies 15, a measurement power supply 17, an amplifier (AMP) 18, an A / D converter 19, and a sampling controller 21 as in the prior art. Is provided. This sampling controller 21
Activate the A / D converter 19 based on the instruction from 1 and
Sample 18 outputs.

Further, the CPU 11 is provided with a storage unit 22 for storing the data converted by the A / D converter 19, and the CPU 11 calculates based on the data stored in the storage unit 22 after the measurement of the DUT 16 is completed. The GO / NO-GO determination of the DUT 16 is performed by executing the processing, and the CRT display unit 20 displays the change over time in the electrical characteristics after the start of the measurement as a waveform together with the determination result.

Next, the operation of the apparatus having the above configuration will be described with reference to the timing chart of FIG. First, when DC parameter measurement starts, the measurement conditions in the test program are
1 and are set in the relay matrix 12 and the analog measurement unit 13. As a result, the analog measurement unit 13
Under the control of the measurement timing controller 14, a required one of the plurality of program power supplies 15 is selected, and a voltage or current for measurement is output from the selected program power supply 15. In the relay matrix 12,
The switches provided at each intersection and indicated by circles in the figure are selectively closed based on the above conditions. This allows
The measurement voltage and current output from the program power supply 15 are supplied to the DUT 16 via the relay matrix 12. The voltage and current output from the DUT 16 in response to the input voltage and current are supplied again to the measurement power supply 17 in the analog measurement unit 13 via the relay matrix 12. The voltage and current measured by the measurement power supply 17 are amplified by the amplifier 18.

On the other hand, when the measurement conditions read from the CPU 11 are supplied to the sampling controller 21, an activation instruction is output from the sampling controller 21 to the A / D converter 19 at certain predetermined time intervals. Each time this instruction is received, the A / D converter 19 samples the output of the amplifier 18 and converts it into digital data.
Supply 1 Also, from sampling controller 21 to C
A signal synchronized with the activation instruction of the A / D converter 19 is supplied to the PU 11, and the CPU 11 sequentially stores the digital data from the A / D converter 19 in the storage unit 22 based on the signal. The number of times the output of the amplifier 18 is sampled is
It is obtained by calculation from the decomposition time of the A / D converter 19 and the measurement time.

After a predetermined measurement time has elapsed, a start instruction is output from the sampling controller 21 to the A / D converter 19 again, and in response to this instruction, the A / D converter 19 samples the output of the amplifier 18 and Convert to digital data,
To supply. Then, as described above, the CPU 11 stores the digital data from the A / D converter 19 in the storage unit 22. Then CPU1
1 reads out the data stored last in the storage unit 22 and executes an arithmetic process, and makes a GO / NO-GO determination based on whether or not the value of this data falls within a certain range. Further CPU1
1 reads out a series of data stored in the storage unit 22, executes arithmetic processing, calculates numerical data with the lapse of time from the start of measurement, and displays the GO / NO-GO on the CRT display device 20.
The characteristic curve is displayed together with the judgment result. FIG. 3 is a flowchart showing a schematic configuration of a program for realizing such an operation. In this flowchart, after the initial data set (initial DATA SET) and the I / O data set (I / O DATA SET) are completed, the A / D converter 1
The number of samplings in 9 is calculated, and the activation interval of the A / D converter 19, that is, the wait time (WAIT) is determined. After that, the timer for measuring the measurement time starts operating,
(TT TIMER), and then the program power supply and the measurement power supply are operated (PWPON). Thereafter, when the timer for measuring the measurement time has completed the time measurement (TT END), sampling is performed by the A / D converter 19, and this is supplied to the CPU 11, whereby a GO / NO-GO determination is performed. Calculation is performed based on the data stored in the storage unit 22, and the characteristic curve is displayed on the CRT display unit 20. Thereafter, measurement is sequentially performed on different test items.

FIG. 4 and FIG. 5 are each a curve diagram showing the change over time of the electrical characteristics of different items of a certain DUT displayed on the CRT display device 20 of the above embodiment.

According to such an apparatus, a temporal change in the measured electrical characteristics can be determined at a glance, and thus, it is not necessary to determine the measurement time by a specialized engineer as in the related art. Also, there is no need to observe using various measuring instruments such as an oscilloscope,
There is no need to collect and process data for each measurement. Therefore, a special technician and a long time for determining the measurement time are not required. Also, since the data of the electrical characteristics of the DUT is stored in the storage unit 22 in the CPU 11, the CRT
The characteristic curve to be displayed on the display unit 20 can be freely reduced or enlarged.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a semiconductor measuring device capable of easily measuring the electrical characteristics of a semiconductor device under optimum conditions in the shortest time. .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration when a semiconductor measuring device according to the present invention is applied to a DC parameter measuring device.
FIG. 3 is a timing chart for explaining the operation of the above-described embodiment, FIG. 3 is a flowchart of a program for realizing the above-mentioned operation, and FIGS. 4 and 5 each show an example of a waveform displayed by the above-mentioned embodiment. FIG. 6 is a block diagram of the conventional device, and FIG. 7 is a timing chart for explaining the operation of the conventional device. 11 ... CPU, 12 ... Relay matrix, 13 ... Analog measurement unit, 14 ... Measurement timing controller, 15 ... Program power supply, 16 ... DUT, 17 ... Measurement power supply, 18 ... Amplifier (AMP), 19 A / D converter, 20 CRT display, 21
... Sampling controller, 22 ... Storage unit.

Claims (1)

(57) [Claims] An analog measuring section for detecting a signal corresponding to an electrical characteristic of a semiconductor device to be measured, and a signal detected by the analog measuring section after a start of measurement in the analog measuring section is sequentially digitalized at predetermined timings. An A / D conversion unit for converting data; a data holding unit for holding the digital data converted by the A / D conversion unit; and a data value last held by the data holding unit falling within a certain range. Determining means for determining whether or not the electrical characteristics of the semiconductor device to be measured are good or not based on whether or not the semiconductor device to be measured is based on data held in the data holding unit after completion of the measurement in the analog measuring unit. A display unit for displaying the electrical characteristics of the device with time and displaying the results of the determination by the determination means.