The Analysis Of DRAM New Fabrication Process And Electric Test Parameter

DRAM (Dynamic Random Access Memory) is one kind of the memory device and it is more and more broadly used in PC and electric area because it has a lot of advantages, such as high density of device, simple architecture, low power and low cost. And due to its advanced fabrication process which made it be the index of semiconductor industry development, usually, the most advanced manufacturing technology always be introduced into DRAM product fabrication first which also leads to thoroughly demonstrate Moore's rule in its development roadmap. DRAM device fabrication also represents the most advanced process level upon some important indexes of semiconductor manufacturing, such as critical dimension, logic bit/unit size, metal layer, mask amount and defect density.This paper starts from the basic knowledge of DRAM device, introduces the types of memory device; DRAM basic architecture, working principle and its chip foot and its working clock, after that, this paper discusses DRAM wafer fabrication process in details, includes AA process, Gate process, Source/Drain process, Cell Capacitor process, Metal Interconnection process, etc. And based on that, from author's engineering experience, discuss some new process of DRAM wafer fabrication and the direction of DRAM technology development. Afterward, based on author's practical experience, this paper emphasizes on the dissertation of electrical test of DRAM product, includes the test parameter, test architecture and test method of wafer parametric test, also includes the test system introduction of wafer unit probe and its test flow and test items. In this section, this paper also discusses some engineering experience about how to improve yield with the help of electric test, in this section, also discusses the engineering case of shorter test time and decrease test cost by SmartTest solution.This paper discusses the DRAM device architecture, working principle, wafer fabrication and assembly process, analysis of its electrical test and focus on the new process in its fabrication area in order to dissertate and figure out the development road of DRAM product in the future; this paper discusses the main parameter of DRAM electrical test in depth as well and from engineering practice, dissertates how to analyze the failure mode of DRAM device, address the source of defect and how to improve manufacturing process based on its electrical test result.