Semiconductor testing circuit and semiconductor testing method

#The present invention relates to a semiconductor testing circuit contributing to a test on the AC characteristics of a semiconductor device such as an LSI, and a semiconductor testing method.

#In a test on the AC characteristics of a semiconductor device, measurements of a propagation delay time, a setup time, a hold time, a response time and so on are made on an input signal and an output signal of the semiconductor device. Generally, in the test configuration, the power supply unit and the measuring unit of an LSI tester are respectively connected to a power supply terminal and a terminal to be tested of the semiconductor device.

#A method of testing the AC characteristics of a semiconductor device will be simply described below. As an example, the following will describe a test on the AC timing characteristics of a logic LSI and so on. When the AC timing characteristics of an input signal are tested, first, a test signal is inputted to a terminal to be tested (an input terminal or an input/output terminal) and a clock signal having a given phase difference beforehand from the test signal is inputted to a clock terminal. Next, a signal latched by a first stage flip-flop connected to the terminal to be tested is compared with an expected value. After that, the delay time and the phase difference of the input signal relative to a reference signal are measured based on the comparison result. On the other hand, when the AC timing characteristics of an output signal are tested, the internal circuit of the semiconductor device is operated to transmit the output signal from a terminal to be tested (an output terminal or an input/output terminal) to the outside of the semiconductor device. After that, the delay time and the phase difference of the output signal relative to the reference signal are measured by comparing the output signal having been transmitted to the outside with the expected value at a desired time.

#FIG. 1 is a schematic diagram showing an example of the test configuration of a semiconductor device including a semiconductor testing circuit according to a first embodiment of the present invention;

#FIG. 2 is a flowchart showing an example of a semiconductor testing method according to the first embodiment of the present invention;

#FIG. 3 is a schematic diagram showing an example of the test configuration of a semiconductor device including a first modification of the semiconductor testing circuit according to the first embodiment of the present invention;

#FIG. 1 schematically shows the test configuration of a semiconductor device including a semiconductor testing circuit according to a first embodiment of the present invention. The semiconductor testing circuit of the first embodiment is used for testing the AC characteristics of an input signal and an output signal of a semiconductor device such as an LSI. The configurations of an LSI tester and the semiconductor device are partially shown in FIG. 1.

#The first embodiment will describe an example of a test on the AC timing characteristics of a semiconductor device including first stage flip-flops and last stage flip-flops which are respectively connected to a plurality of input/output terminals. As a matter of course, the use of the semiconductor testing circuit and the semiconductor testing method of the present invention is not limited to the semiconductor device configured thus.

#As shown in FIG. 1, a semiconductor testing circuit 100 is provided in a semiconductor device 200 that is a device to be measured. The semiconductor device 200 is mounted on a load board 400 acting as an interface connecting the semiconductor device 200 and an LSI tester 300 during a test. The semiconductor device 200 may be mounted on a wafer or molded in a package. The LSI tester 300, the semiconductor device 200, and the semiconductor testing circuit 100 will be described in this order.