Si{sub}(1-x)Ge{sub}x/Si triple barrier resonant tunneling diode with a high peak-to-valley ratio at room temperature

摘要

We have theoretically analyzed that the use of a combination of electron tunneling and multiple wells is very effective in enhancing the negative-differential-resistance (NDR) characteristics for a SiGe resonant tunneling diode (RTD), and have demonstrated that an electron-tunneling triple-barrier RTD exhibits a high peak-to-valley current ratio (PVCR). We have further improved the growth layer crystal quality by the use of the proposed annealed thin double-layer strain-relief buffer, and an electron-tunneling asymmetric triple-barrier RTD with this buffer exhibits a PVCR of ～180 which is ～150 times as high as those reported by other researchers and is comparable to the values obtained from III-V RTDs. The results also indicate that nonelastic scattering is little caused inherently in the SiGe RTD.