A memory wafer testing method and memory testing machine

Abstract

The present invention provides a method for testing memory wafers and a memory testing machine. Before performing wafer needle testing such as functional testing, the testing method first performs a group short-circuit test on the same test memory chips on the wafer to determine whether the wafer is invalid. , and only after the wafer passes the short-circuit test, the memory tester is run for wafer needle testing, thereby avoiding the large leakage current of the failed wafer such as the probe card when the tester directly performs needle testing on the failed wafer In the event of damage, at the same time, bad chips can be found and removed as early as possible, reducing the average testing time of wafer testing and reducing testing costs. The memory testing machine provided by the present invention is provided with a grouping management unit, which can carry out probe grouping on the probe cards, and ground the pins of the memory chips under test in the grouping for short-circuit testing, thereby protecting the testing machine. This avoids the situation that the probe card and the like are damaged by the large leakage current of the failed wafer when the testing machine directly performs pin testing on the failed wafer.

Description

technical field [0001] The invention relates to the technical field of semiconductor testing, in particular to a memory wafer testing method and a memory testing machine. Background technique [0002] In 1947, the birth of the first transistor marked the beginning of the semiconductor industry. Since then, semiconductor production and manufacturing technology has become more and more important. Many single transistors in the past can now be interconnected and processed into a complex integrated circuit form. This is what the semiconductor industry is currently manufacturing called "very large scale" (VLSI, Very Large Scale Integration) integrated circuits, usually containing millions or even Tens of millions of gate transistors. Semiconductor circuits were originally manufactured in wafer form. A wafer is a circular silicon chip. On the basis of this semiconductor, many independent individual circuits are established. This single circuit on a wafer is called a die (that is...

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Problems solved by technology

However, in the process of using a tester with a high number of simultaneous measurements for wafer probe testing, all the DUTs for the same test are usually powered on at the same time, which can easily lead to excessive wafer leakage of failed chips and damage the probe card of the tester. The root cause of this phenomenon is: during the test process using the high-quality testing machine (KALOS testing machine of the 768 testing machine), since the test channel does not have a power protection circuit, the machine uses the test channel to send power to the wafer. The maximum current of the test power supply provided by the DUT cannot exceed 10mA, and the leakage current in the central area of ​​the leakage wafer will be as high as 45mA (the current of a normal wafer is below 1mA). This ultra-high leakage current will flood into the test channel and eventually damage the test. machine probe card

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