Abstract: A system and method for testing semiconductor memory devices includes a variable voltage input to a memory cell control gate. The voltage to the control gate can be varied from a voltage level used for normal memory cell operation, such as a read operation, to a voltage level that can be used to detect a defect in the memory device. During testing, the voltage level applied to the control gate is lower than the voltage level applied to a second terminal, such as a drain terminal, of the memory cell. In some embodiments, testing for defects can include applying a negative voltage to the control gate, while a positive voltage is applied to the drain terminal, which can reveal the presence of a gate-to-drain leakage defect.

Abstract: A method of testing a semiconductor memory device includes reading previously written test data from the semiconductor memory device simultaneously through at least two data I/O connections, e.g., pins or pads, of the semiconductor memory device. The signals from the two data I/O connections are combined to produce a compound output signal. The compound output signal is received by a single I/O channel of a tester. The tester compares the compound output signal to a predetermined voltage level, and determines whether the semiconductor memory device is operating properly based on the comparison of the compound output signal to the predetermined voltage level.

Abstract: A method of detecting manufacturing defects at a memory array may include utilizing test circuitry to provide a selected voltage as drain bias on a bit-line of the memory array where the memory array is configured to employ a first voltage as the drain bias for a read operation and the selected voltage is higher than the first voltage, and determining whether a leakage current indicative of a manufacturing defect between the bit-line and another component of the memory array is present responsive to providing the selected voltage as the drain bias. A corresponding test device is also provided.

Abstract: A method of screening manufacturing defects at a memory array may include programming a background pattern of physically inverse data along conductive lines extending in a first direction. The programming may include providing a program conductive line with a high value. The method may further include programming a memory cell at an intersection of the program conductive line and a conductive line extending in a second direction to a selected high value, and determining whether a cell initially at a low value and associated with a conductive line extending in the first direction and adjacent to the program conductive line is disturbed.

Abstract: A method of detecting manufacturing defects at a memory array may include utilizing test circuitry to provide a selected voltage as drain bias on a bit-line of the memory array where the memory array is configured to employ a first voltage as the drain bias for a read operation and the selected voltage is higher than the first voltage, and determining whether a leakage current indicative of a manufacturing defect between the bit-line and another component of the memory array is present responsive to providing the selected voltage as the drain bias. A corresponding test device is also provided.

Abstract: A system and method for testing semiconductor memory devices includes a variable voltage input to a memory cell control gate. The voltage to the control gate can be varied from a voltage level used for normal memory cell operation, such as a read operation, to a voltage level that can be used to detect a defect in the memory device. During testing, the voltage level applied to the control gate is lower than the voltage level applied to a second terminal, such as a drain terminal, of the memory cell. In some embodiments, testing for defects can include applying a negative voltage to the control gate, while a positive voltage is applied to the drain terminal, which can reveal the presence of a gate-to-drain leakage defect.

Abstract: A method of testing a semiconductor memory device includes reading previously written test data from the semiconductor memory device simultaneously through at least two data I/O connections, e.g., pins or pads, of the semiconductor memory device. The signals from the two data I/O connections are combined to produce a compound output signal. The compound output signal is received by a single I/O channel of a tester.

Abstract: A method of screening manufacturing defects at a memory array may include programming a background pattern of physically inverse data along conductive lines extending in a first direction. The programming may include providing a program conductive line with a high value. The method may further include programming a memory cell at an intersection of the program conductive line and a conductive line extending in a second direction to a selected high value, and determining whether a cell initially at a low value and associated with a conductive line extending in the first direction and adjacent to the program conductive line is disturbed.