Pseudo-Static 1T Capacitorless DRAM using 22nm FDSOI for Cryogenic Cache Memory

Electron charge sensor with hole current operating at cryogenic temperature

“…Note that carriers injected into the MOSFET body have long lifetimes at cryogenic temperatures. 18) As a preliminary experiment, we measured the time dependence of the PMOS output current after charge injection and confirmed that the current change was within the noise floor level of the measurement system even as long as ten minutes after the injection. Since electrons are stably trapped in SGS-dot, they can be transferred back to SG3-dot after measurement if desired.…”

“…When SOI-PMOS is executed in the same way as a capacitor-less one-transistor Dynamic Random Access Memory (1-T DRAM), electron charges can be converted into hole currents that amplify the signals, thus enabling highly sensitive electron-charge sensing. [14][15][16][17][18][19][20] This is what a Si quantum computer using electron spins needs to read out. In contrast to room temperature operation, electrons injected into the body of the PMOS at cryogenic temperatures have a much longer lifetime, resulting in a quasi-static current output.…”

“…In contrast to room temperature operation, electrons injected into the body of the PMOS at cryogenic temperatures have a much longer lifetime, resulting in a quasi-static current output. 18) Our idea is to combine this PMOS sensor with previously reported techniques for stable charge confinement and transport in MOS structures that take advantage of the cryogenic properties of low thermal fluctuations, [21][22][23][24][25][26][27][28][29] thereby enabling the use of standard LSI technology for the measurement of Si quantum computers.…”

“…We also found that the Vth and subthreshold swing (SS) of FG and SG exhibited similar characteristics to the previously reported temperature dependence. 18,30) Considering these electrical characteristics at 5 K, we devised a sequence for supplying electrons to SG3-dot.…”