JPH0357239A - Test circuit pattern for semiconductor - Google Patents

Abstract

PURPOSE:To shorten a measuring time by a method wherein a series connection circuit which is formed on a semiconductor wafer and which is composed of constant current circuits and of MOS diodes is constituted so that an electric current can be applied simultaneously to each MOS. CONSTITUTION:Constant current circuits are formed in series with MOS diodes 2 and individual circuit patterns are connected in parallel with a voltage source 3 to constitute a measuring circuit. When a voltage drop is measured at this time, a voltmeter 4 which can be scanned in a time-sharing manner is used. In conventional cases, it took several seconds to several tens of seconds to measure one point; in some cases, several hundred points had to be measured; it took a considerable time for this measurement. By this method, a measuring operation has nothing to do with the number of measuring points; a measuring time is only a longest point time which elapses until a MOS diode in a pattern is broken down; thereby, a whole measuring operation can be finished in this point time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a test circuit pattern formed on a semiconductor wafer. [Summary of the invention 1] The present invention incorporates a constant current circuit into the test circuit pattern provided at predetermined locations on a semiconductor wafer, thereby reducing the time required to perform measurements at several to hundreds of locations, which would previously take tens of hours. This problem was solved. [Prior art 1] Conventionally, the test circuit pattern provided at the required location on a semiconductor wafer has the configuration shown in Fig. 2, and a current source is connected to this to form the test circuit shown in Fig. 4 for testing. The characteristics of a large number of MOS dies formed as circuit patterns were sequentially tested. [Problem to be solved by the invention] However, in the above configuration, each MOS guide is measured sequentially, so it takes a long time to measure from several to several hundred locations.
The problem was that it could take dozens of hours in some cases. The present invention aims to provide an improved test circuit pattern that solves the above problems. Means for Solving 1 Problem] The means adopted by the present invention to achieve the above object is to configure a series connection circuit of a constant current circuit and a MOS diode as a test circuit pattern. [Action I By providing a constant current circuit in series with the MOS diode,
The actual test and measurement circuit can have the configuration shown in Figure 3, so the measurement circuit is constructed by connecting a voltage source in parallel to each circuit pattern. Therefore, by time-sharing the voltmeter V, it becomes possible to measure a large number of measurement points in a short time.

[Example] Examples will be described below using a constant current TDDB test as an example. Constant current TDDB is from 0.01A/cm” to several tens of A
The time it takes for a MOS die to break down when a constant current of up to / crn' is applied. Here, the time to break down refers to the time it takes for the voltage to drop below a certain value. When measuring, for example, several to hundreds of locations on a wafer, a current circuit is connected to each MOS die in each pattern, so a voltage source is connected to each pattern on the wafer at the same time. The measurement circuit shown in Figure 3 can be constructed. The voltage drop at this time is established using a voltmeter capable of time-division scanning. Therefore, conventionally it takes several seconds to t'l l O
The measurement time that used to take several minutes, and in some cases could take tens of hours overall for measurements at hundreds of locations, is now independent of the number of measurement locations.
The measurement time is only the point time that takes the longest time until the MOS diode in the pattern breaks down, and the overall -11 constant is completed. [Effects of the invention] By incorporating a constant tit current circuit into the test vacuum, it became possible to energize each MOS at the same time.
This can significantly shorten the time required for measurements such as the constant current TDDB test described above.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a test circuit pattern showing an embodiment of the present invention, FIG. 2 is a diagram showing a conventional test circuit pattern,
3 is a block diagram of a measuring circuit using the test circuit pattern of FIG. 1, and FIG. 4 is a block diagram of a test circuit using the test circuit pattern of FIG. 2.・Constant current circuit ・MOS die capacitor ・Voltage source ・Voltmeter for time division scanning ・Ammeter ・Voltmeter Test circuit pattern part in semiconductor wafer ・Test circuit B turn part and above in semiconductor wafer

Claims (1)

[Claims] A test circuit pattern for semiconductors formed on a semiconductor wafer and consisting of a series connection circuit of a constant current circuit and a MOS diode.