Low-temperature integrated process below 500° C for thinTa₂O₅ capacitor for giga-bit DRAMs

摘要

A new low-temperature integrated (LTI) process has been developedfor giga-bit DRAMs with a thin Ta₂O₅ capacitor.The maximum process temperature after capacitor formation is restrictedto lower than 500° C in the LTI process. This process can reduce thecapacitor leakage current by approximately four orders of magnitude incomparison with conventional high-temperature processes. A ten timesimprovement in data-retention time has been verified in an experimentalDRAM device with 2.5 nm Ta₂O₅ capacitors by theLTI process