A New BJT Selector for sub-0.02µm² High Density Embedded PCM Memory in FDSOI CMOS Technology

Fabrication and electrical characteristics of a new BJT selector enabling a 1T1R embedded phase change material (ePCM) memory cell of 0.019µm ² are extensively reported in this paper. A smart process, leveraging the specific feature of the FDSOI substrates with its thin buried oxide (BOX) has been developed to create an innovative isolation wall between bitlines (BL) and to totally suppress the parasitic BL-to-BL leakage. A current of 300µA at V EB =1.6V and a leakage as low as 8pA/cell at V BE =3.6V, 165°C were achieved. Compared to its MOS selector counterpart, -48% cell area reduction is obtained at same driving current, demonstrating the high density and the cost competitiveness of this FDSOI BJT selector solution. Finally, a shrunk BJT-ePCM cell of 0.015µm ² , which is the smallest 1T1R eNVM reported to date, is demonstrated for the first time.