Why SRAM is costlier to DRAM ?

While at the time of fabrication, DRAM also required cap which is formed using Trench in cmos process. On the other hand in SRAM, all components are transistors only which is easier to fabricate.

Also tell me how 1T DRAM (1mos+1cap) is taking more area as compare to 6T SRAM( 6 mos transistors) ? Is capacitor not taking much area (i mean 8 or 9 times of single mos)???

what I know is DRAM cell takes less space than SRAM cell. That's why we have higher density DRAM's compared to SRAM in same die size.

malli_1729 said:

what I know is DRAM cell takes less space than SRAM cell. That's why we have higher density DRAM's compared to SRAM in same die size.

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yeah ...
any idea about the cost ?

Static RAM typically holds the value in a circuit that is the equivalent of a flip-flop (which is stable over time as long as power is applied), while dynamic RAM holds the value as a charge on a capacitor (which leaks away over time and therefore needs to be refreshed on a regular basis).
Simplistically, you need 2 devices (such as transistors) to make a flip-flop but can get away with 1 transistor and a capacitor for the SRAM. Therefore you can think of a DRAM as taking half of the components as a SRAM.
Of course implementations differ and the DRAM requires refresh circuitry but the principle still holds.
Therefore, as cost is directly related to the complexity of the design (i.e. the number of components and the interconnections required) and the DRAM takes less space than the SRAM, the cost of DRAM is generally lower, all other things being equal.
Susan