System for testing integrated circuit devices

Abstract

A voltage generating circuit for generating internal voltage for a packaged integrated circuit memory device, is controllable to provide incremental adjustments in the voltage for testing of the memory device. The voltage generating circuit permits internally generated voltages of the memory device, such as the substrate voltage Vbb, the DVC2 voltage, and the pumped voltage Vccp, to be controlled externally through the application of test signals via the conventional test function, in performing standard device tests such as the static refresh test, logic 1s and 0s margin testing, and the like for packaged memory devices. Also, programmable circuits including programmable logic devices, such as anti-fuses, are provided that are programmable to maintain the voltage at a magnitude to which it is adjusted.

Description

[0001] This application is a Continuation of U.S. application Ser. No. 10 / 835,945, filed Apr. 30, 2004, which is a Continuation of U.S. application Ser. No. 10 / 295,499, filed Nov. 15, 2002, now U.S. Pat. No. 6,756,805, which is a Divisional of U.S. application Ser. No. 08 / 916,994, filed Aug. 21, 1997, now U.S. Pat. No. 6,496,027, all of which are incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention relates to semiconductor integrated circuits, and in particular, the invention relates to a method and a voltage generating circuit for allowing packaged part testing of semiconductor integrated circuits by controlling internal voltages of the integrated circuits. BACKGROUND OF THE INVENTION [0003] Semiconductor integrated circuit devices, such as dynamic random access memory (DRAM) devices, undergo a tremendous amount of testing at various steps in the production process. Typically, DRAM devices are tested by using write and read operations to determine wh...

AI Technical Summary

Benefits of technology

The present invention provides a circuit and system for testing the functionality of an integrated circuit device. The circuit generates an internal voltage for the device and can adjust its value to control various functions, such as the refresh time of the memory cells. The system includes a voltage generating circuit, a test mode enabling circuit, and a test mode circuit for producing different test signals. The method involves applying the test signals to a control circuit in sequence to adjust the internal voltage. The invention allows for efficient and integrated testing of the device, saving time and reducing the time-to-market.

Problems solved by technology

Consequently, testing an array of memory cells requires a substantial amount of time.

Consequently, the test time for a single memory chip can be excessive and when several hundred such chips on a wafer are tested sequentially the test time is considerable.

The requirement that solid state memory devices be tested exhaustively, and the time required to perform these tests, greatly impact on the cost of the semiconductor devices.

In many cases, this margin test procedure is conducted by hand, which is a very time intensive process.

Consequently, there is a high risk that the semiconductor device may be damaged during the testing process or in removing the packaging for conducting the margin test.

Accordingly, procedures have been developed, although not universally accepted.

One shortcoming of this arrangement is that tests that require memory read or write operations cannot be performed when externally forcing either of these pins.

As technology advances decrease the feature size of the semiconductor elements and demands are made to increase the capacity of the memory array, the memory is more prone to defects that damage memory cells of memory devices.

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