US 5,512,842 AGranted

High accuracy inspection method and apparatus of semiconductor integrated circuits

AssigneeNEC Corporation

InventorTomoyuki Kida

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Abstract

An inspection method and apparatus of semiconductor integrated circuits, in which a specification, a measuring system error in measurements and a number N of measurement repeat times are read in and a distance between parts of the semiconductor integrated circuit is measured to obtain measured value. The measured value is compared with the specification to execute a first non-defective/defective discrimination. The measured value determined to be defective by the first discrimination is further compared with a new discrimination reference obtained by adding the measuring system error to the specification to execute a second non-defective/defective discrimination. Against the semiconductor integrated circuits discriminated to be defective in the first discrimination and to be non-defective in the second discrimination, the measurement is carried out N times and an average value of the N number of measured values is calculated. This average value is further compared with the specification to execute a third non-defective/defective discrimination. As a result, the measuring system error components are averaged and thus a false notice rate of the essentially non-defective ICs can be reduced.

Claims13

Dependent claims

A method of inspecting semiconductor integrated circuits, in which a distance between predetermined parts of each semiconductor integrated circuit is measured to obtain a measured value and the measured value is compared with a predetermined specification of the distance to discriminate a non-defective/defective status of the semiconductor integrated circuit, comprising:

a parameter reading step for reading the specification, a measuring system error, made by a measuring system, in the measurement and a number N (N:
a natural number of at least 2) of repeat times of the measurement;
a measuring step for measuring the distance to obtain the measured value;
a first inspection step for comparing the measured value obtained in the measuring step with the predetermined specification to discriminate the non-defective/defective status of the semiconductor integrated circuit, wherein when a difference greater than a predetermined value exists between the measured value and the predetermined specification, the difference is indicative of a defective status and wherein when a difference less than said predetermined value exists between the measured value and the predetermined specification, the difference is indicative of a non-defective;
a second inspection step for comparing the measured value, discriminated to be defective in the first inspection step, with a discrimination reference, said discrimination reference being calculated by adding the measuring system error to the specification to discriminate the non-defective/defective status of the semiconductor integrated circuit;
an average value calculation step for repeatedly executing the measuring step for the semiconductor integrated circuit which is discriminated to be defective in the first inspection step and to be non-defective in the second inspection step to calculate an average value of the N number of measured values obtained in the N times of repeated measuring steps;
and
a third inspection step for comparing the average value with the specification to discriminate the non-defective/defective of the semiconductor integrated circuit.

5 more elements

An apparatus for inspecting semiconductor integrated circuits, in which a distance between predetermined parts of each semiconductor integrated circuit is measured to obtain a measured value and the measured value is compared with a predetermined specification of the distance to discriminate a non-defective/defective status of the semiconductor integrated circuit, comprising:

parameter reading means for reading the specification, a measuring system error in the measurement and a number N (N:
a natural number of at least 2) of repeat times of the measurement;
measuring means for measuring the distance to obtain the measured value;
first inspection means for comparing the measured value obtained by the measuring means with the specification to discriminate the non-defective/defective status of the semiconductor integrated circuit, wherein when a difference greater than a predetermined value exists between the measured value and the predetermined specification, the difference is indicative of a defective status and wherein when a difference less than said predetermined value exists between the measured value and the predetermined specification, the difference is indicative of a non-defective;
second inspection means for comparing the measured value discriminated to be defective by the first inspection means with a discrimination reference calculated by adding the measuring system error to the specification to discriminate the non-defective/defective status of the semiconductor integrated circuit;
average value calculation means for repeatedly executing the measurements against the semiconductor integrated circuit which is discriminated to be defective by the first inspection means and to be non-defective by the second inspection means to calculate an average value of the N number, of measured values obtained in the N times of repeated measurements;
and
third inspection means for comparing the average value with the specification to discriminate the non-defective/defective status of the semiconductor integrated circuit.

5 more elements

Dependencies are inferred from the claim text.