Apparatus and method for measuring performance of memory array

A method of measuring an operation of a memory array, comprising:

• applying a plurality of testing operational voltages to the memory array;
• for each of the testing operational voltages,
• performing a writing operation to write an expected data pattern to the memory array;
• performing a reading operation to the memory array to obtain a read data pattern;
• and
• performing a comparing operation to compare the read data pattern to the expected data pattern for determining a performance failure.

A test apparatus, disposed in a scribe line of wafer, comprising:

• a first test pad, receiving a minimum testing voltage;
• a second test pad, receiving a maximum testing voltage
• a memory array;
• a built-in self-test (BIST) circuit, electrically connected to the test pads and the memory array, dividing a range of voltage between the minimum testing voltage and the maximum testing voltage into a plurality of testing voltages, and programmed to perform the following steps:
• respectively performing a memory array operation test on the memory array for each of the testing voltages, wherein the testing voltages are provided for operating the memory array;
• detecting an occurrence of a failure in the memory array in a failure memory array operation test;
• and
• outputting the testing voltage corresponding to the failure memory array operation test as a minimal operation voltage of the memory array through a third test pad.