Design methodology and manufacturing method for semiconductor memory

A manufacturing method for a semiconductor memory, the method comprising the steps of:

• designing a DRAM memory array containing a DRAM memory cell;
• verifying said designed DRAM memory array;
• and
• forming said verified DRAM memory array on a semiconductor wafer,
• wherein said step of verifying the DRAM memory array includes:
• a first step of determining, with respect to a plurality of parameters each serving as a component affected by an increase/decrease in a read-out signal of said DRAM memory cell and having a statistical distribution by assuming each manufacture fluctuation, each value of the parameters based on a random number in the distribution per set of said plurality of parameters;
• a second step of providing a formula defining the read-out signal of said DRAM memory cell, and applying the value of each of said determined parameters to said formula to calculate the read-out signal of said DRAM memory cell;
• a third step of determining quality of said DRAM memory cell based on the read-out signal of said calculated DRAM memory cell;
• and
• a forth step of performing said first to third steps to each of a plurality of DRAM memory cells said DRAM memory cell contains to calculate the number of good or failed DRAM memory cells in said DRAM memory array.

A semiconductor design device realized by using a computer, the device comprising said computer including:

• storing preliminary an equation defining a characteristic of a memory cell and a plurality of parameters each serving as a component for defining the characteristic of the memory cell and having a statistical distribution by assuming each manufacture fluctuation;
• generating a random number and determining each value of the parameters based on said generated random number from the distribution per set of said stored plurality of parameters;
• calculating the characteristic of said memory cell by substituting said determined value of each of the parameters into said stored equation;
• determining quality of said memory cell based on said calculation result;
• and
• performing a processing of determining each value of the parameters and a processing of calculating the characteristic of said memory cell and determining the quality of said memory cell by the number of times equal to that of memory cells preset.