SU1539696A1 - Method of rejection of integral circuits - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to microelectronics, namely to control in the manufacture of integrated circuits. The purpose of the invention is to increase the reliability and reduce the time of rejection of integrated circuits with defects; this is achieved by controlling the amount of current at the initial part of the current-voltage characteristic of the PH-transitions of the integrated circuit at their forward bias and by controlling the parameters of the current-voltage characteristic Many parallel-connected transitions on a chip, the method of combining which through standard pins of the microcircuit is given in the description. 3 il.

Description

The invention relates to microelectronics, namely the manufacture of integrated circuits.

The purpose of the invention is to increase the reliability and reduce the time of rejection of chips with defects.

FIG. 1 is a diagram of connecting the integrated circuit to the meter current-voltage characteristics; in fig. 2- examples of connecting the outputs of an integrated circuit for semiconductor structures with different types of conductivity; in fig. 3 - examples of current-voltage characteristics.

It is known that the current-voltage characteristic of a biased p-p junction is non-linear and has the form given in yig. 3 (pos. 3).

FIG. 1 The following notation is accepted: 1 — integrated circuit; 2 meter current-voltage characteristics.

In the process of manufacturing integrated circuits, a variety of foreign matter in the form of dust particles or residues of chemical elements from previous manufacturing operations leading to defects can get onto the semiconductor wafer, which is the basis for forming the structures of the integrated circuit. In this case, the vrlt-ampere characteristic k. The pn-junction has a linear appearance in its initial part and is characterized by an angle of 5 slope, the magnitude of which is directly proportional to the contamination of the pn-junctions of the integrated circuit with impurities. As a rule, leakage currents due to such contamination are very small and require to be detected.

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measuring at the sensitivity limit of the current-voltage characteristics meter (microcurrent mode).

In the integrated circuit, having a current-voltage characteristic, during its operation over time, under the action of an electric current, the structure of the pn junction degrades, leading to an increase in leakage currents and, ultimately, to the malfunction of the integrated circuit. When implementing the method, the current-voltage characteristic of several pn-junctions located throughout the crystal and connected in parallel is monitored to increase sensitivity and reliability.

To do this, all the conclusions of the integrated circuit must be included according to the scheme drawn up with the following rules:

each output of the integrated circuit must be connected to the + or - meter of the current-voltage characteristic so that the pn-junction of the semiconductor structure included in the integrated circuit and connected to this output is shifted in the forward direction;

between + and - the meter of the current-voltage characteristic should include the largest possible number of directly biased pn-junctions of the semiconductor structures of the integrated circuit;

Between the + and - meters of the volt-ampere characteristic should not be included the structures of the integrated circuit having a linear volt-ampere characteristic (for example, resistor voltage dividers).

After connecting the outputs of the integrated circuit, remove the total

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current-voltage characteristic of an equivalent two-pole device resulting from connecting the leads. In this case, the presence of defects, including those caused by the contamination of the crystal, should be judged by Comparing with the current value obtained for a knowingly working and reliable chip at the initial part of the current-voltage characteristic of an equivalent two-pole device

offset. The excess current at the initial portion of the current-voltage characteristic over the value of the reference chip indicates the unreliability of the test chip and is a criterion for rejection.

Claims (1)

Formula isobteni The method of rejecting integrated circuits, which consists in choosing pairs of pins of controlled integrated circuits between which pn junctions are contained, serves on the selected pairs of pins of an integrated circuit a linearly increasing voltage and registers a predetermined portion of the current-voltage characteristic, determines the value of the informative parameter where defective integrated circuits are rejected, characterized in that, in order to increase the reliability and reduce the time of rejection, before starting the rejection of the volume all selected pairs of pins are inserted. so that the pn junctions of the integrated circuit are connected in parallel, the initial portion of the volt ampere characteristic of the pn junction is selected as the specified part of the volt-ampere characteristic, and the value of leakage current. 1 ± TgFig .1 - Fig-t fig.Z and