Integrated Gountum Devices using Fluoride Heterostructures

研究了Al/CaF_2/CdF_2/CaF_2/Si异质结构与传统Si- mosfet在同一Si衬底上的协整谐振隧道二极管（rtd）。首先，我们成功地在场氧化层的接触孔中制造了rtd。然后从RTD特性和欧姆接触特性两方面对离子注入剂量进行了优化。结果表明，在10^<16>cm^<-2>的磷离子注入退火后，硅表面在原子尺度上变得粗糙。另一方面，在我们的工艺中，形成非合金欧姆触点需要10^<15>cm^<-2>或更多。基于这些工艺限制，我们提出了在同一衬底上制造rtd和MOSFET的工艺。我们制作了由2个rtd和1个FET组成的测试电路，可以作为锁存门或位SRAM单元。在制作电路上，我们获得了RTD和FET的正常工作，并观察到两个RTD串联连接上的锁存操作。

Co-integration of resonant tunneling diodes (RTDs) which were composed of heterostructure of Al/CaF_2/CdF_2/CaF_2/Si and conventional Si-MOSFETs on a same Si substrates was investigated. First, we succeeded in fabricating the RTDs in contact holed made in a field oxide layer. And then, we optimized dose of ion implantation from both of RTD characteristics and Ohmic contact properties. It is found that Si surface became rough in the atomic scale level if phosphorus ions over 10^<16>cm^<-2> were implanted and annealed. On the other hand, 10^<15>cm^<-2> or more was necessary for forming non-alloy Ohmic contacts which is necessary in our process.On the basis of these process limitation, we propose a process fabricating the RTDs and MOSFET on the same substrate. We fabricated test circuit composed of 2 RTDs and 1 FET which can operate as a latch gate or one bit SRAM cell. On the fabricated circuit, we obtained normal operation of RTD and FET, and observed latch operation on the series connection of the two RTDs.