JPH03214080A - Evaluating system for lsi device - Google Patents

Abstract

PURPOSE:To compare results of actual measurement with results of analysis by storing results of analysis on a change in internal voltage of an LSI device obtained by a moderate analysis of a circuit simulation to output them at optional time intervals. CONSTITUTION:After converted into digital from analog, a voltage data measured with a EB tester 10 is stored into a section 20 for storing results of actual measurement. Numerical data thus stored is converted 30 to a graph to be outputted as graph file 40. Voltage characteristic at points of a wire undergoes a transient analysis pertaining to a designing circuit to an LSI device beforehand and all analysis data are stored into a section 50 for storing the results of analysis as numerical data. Then, when measuring 10 a voltage, an analysis data corresponding to a measuring point is outputted from the storage section 50 (storing means) at a time interval the same as a measuring interval with the tester 10 to be converted 60 to a graph data and outputted as graph file 70. After coupled at a graph data coupling section 80 (comparison means), the graph files 40 and 70 are shown in graph on a graph data display section 90.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an LS device used for evaluation testing of LSI devices.
Regarding an I-device evaluation system.

<Prior Art> In designing LSI devices, circuit simulation is performed using a computer in order to confirm the operation of a designed logic circuit.

The LS device that has been prototyped through circuit simulation is tested by a tester, and adjustments are made to the analysis results from the circuit simulation.

Testers and circuit simulators are used in such LSI device evaluation work. Recently, as a tester, an EB tester that performs no-load probing using an electron beam has been frequently used. and,
The EB tester and the circuit simulator are operated at the same time, and the analysis results obtained by the circuit simulation are compared with the actual measurement results obtained by the EB tester at regular intervals. [1
The road simulation data used is data output at regular intervals based on data internally analyzed by the circuit simulation program.

<Problem to be solved by the invention> By outputting analysis data from a circuit simulator at regular intervals, it becomes possible to compare actual measurement results from an EB tester and analysis results from a circuit simulation. is not constant. In other words, depending on the transient characteristics of each part of the LSI device,
The time required for the analysis varies, and generally speaking, the more important parts require longer analysis time. Nevertheless,
In the conventional comparative evaluation method in which analysis data is output from a circuit simulator at regular intervals, a problem arises in that sufficient analysis is not performed on highly important parts.

In other words, although circuit simulators are capable of performing highly accurate circuit simulations, in reality, LSI devices are evaluated based on insufficient analysis results, and this problem is rather important. This occurs in highly sensitive areas, making LSI device evaluation work inaccurate.

The present invention was made in view of the above circumstances, and is not affected by the analysis time interval by circuit simulation.
It is an object of the present invention to provide an LSI device evaluation system that can accurately compare highly accurate analysis results with actual measurement results by a tester.

<Problems to be Solved by the Invention> The evaluation system according to the present invention includes a tester that measures internal voltage changes of an LSI device at predetermined time intervals, and a tester that measures internal voltage changes of an LSI device obtained through transient analysis of circuit simulation. A storage means for accumulating the analysis results of and outputting them at arbitrary time intervals, and a comparison means for comparing the actual measurement results measured by the tester and the analysis results output from the accumulation means. It is said that

<Function> Equipped with an accumulation means for accumulating analysis results from circuit simulation, and has a circuit simulation function.
There is no need to use a circuit simulator when measuring voltage changes with a tester.

When the tester measures voltage changes, the analysis results accumulated in the accumulation means can be output in accordance with the measurement interval. Therefore, as long as the comparison start time and comparison end time are constant, the analysis results from the circuit simulation and the actual measurement results from the tester can be accurately compared without being affected by the measurement interval of the tester or the analysis time interval in the circuit simulation. be done. Furthermore, the storage means can store highly accurate analysis results that have been analyzed over a sufficient amount of time in advance.

<Example> Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an example of an LSI device evaluation system according to the present invention.

The LSI device evaluation system uses an EB tester 10. The EB tester IO sequentially measures the voltage characteristics of various parts of the wiring at predetermined time intervals by probing the internal wiring of the LSI device with an electron beam without load.

The voltage data measured by the EB tester 10 is converted from analog to digital and then stored in the actual measurement result storage section 20 as numerical data. The numerical data accumulated in the actual measurement result accumulation section 20 is subjected to data conversion for displaying a graph in a graph data conversion section 30, and is output as a graph file 40.

On the other hand, with regard to the designed circuit of the LSI device, the voltage characteristics of various wiring locations are subjected to transient analysis, and all of the analysis data is stored as numerical data in the analysis result storage section 50 (storage means).

When the voltage is measured by the EB tester IO, analysis data corresponding to the measurement location is output from the analysis result storage section 50 at the same time interval as the measurement interval by the EB tester 10. The analysis data output from the analysis result storage section 50 is subjected to data conversion for displaying a graph in a graph data conversion section 60, and is output as a graph file 70.

In this way, the corresponding voltage data and analysis data are transferred from the graph data converter 30.60 to the graph file 40.60.
70 and is output synchronously. Graph data conversion section 3
Graph files 40 and 70 output from 0.60 are
After being combined in the graph data combining section 80 (comparison means), the data is displayed in a graph on the graph data display section 9o.

Figure 2 (a) is a graphical representation of the actual measurement results by EB tester 1o, Figure 2 (b) is a graphical representation of the analysis results by circuit simulation, and Figure 2 (C) is the actual measurement results by EB tester 10. This is a graphical representation of the combination of the data and the analysis results from circuit simulation.

All analysis data from the circuit simulation is stored in advance in the analysis result storage unit 50 (storage means), and at the measurement stage by the EB tester 10, the corresponding voltage data and analysis data are synchronously converted by the graph data conversion units 30 and 60. Therefore, the actual measurement results from the EB tester 10 and the analysis results from the circuit shimmy range can be accurately compared on the same graph, even if analysis results obtained over a sufficient amount of time are used.

<Effects of the Invention> As is clear from the above description, according to the LSI device evaluation system of the present invention, even when the internal wiring voltage of an LSI device is measured at a time interval different from that in analysis by circuit simulation, The actual measurement results and the analysis results based on circuit simulation can be accurately compared without any time lag.

In addition, there is no need to match the calculation interval of analysis data with the measurement interval of the tester, and it is possible to perform transient analysis over a sufficient amount of time, making it possible to compare highly accurate analysis results with actual measurement results. Device evaluation accuracy is improved.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of an evaluation system according to the present invention, and FIG. 2(a) shows actual measurement results by an EB tester.
FIG. 2(C) is a graph showing the results of analysis by circuit simini-resion, and FIG. 2(C) is a graph showing combined data of the results of actual measurement by an EB tester and the results of analysis by circuit simulation. 10...EB tester 50...Accumulation means 80...Comparison means

Claims (1)

[Claims] (1) A tester that measures internal voltage changes of LSI devices at predetermined time intervals and a tester that accumulates the analysis results of internal voltage changes of LSI devices obtained through transient analysis of circuit simulation, and then displays them at arbitrary time intervals. 1. An LSI device evaluation system comprising: an accumulation means for outputting an output from the tester; and a comparison means for comparing an actual measurement result measured by the tester with an analysis result output from the accumulation means.