No abstract

No abstract

Journal of the Electron Devices Society 6 V. CONCLUSION With incumbent flash memory devices operated in the range of 15-17 V, it is imperative to pursue green flash memory that can be operated at voltage less than 10 V to realize a sustainable environment. In this paper, two promising CTL types based on crystalline oxide including crystalline high-k dielectric and crystalline oxide semiconductor which possess the capability to achieve this goal are reviewed. For CTL based on crystalline high-k dielectric, the distinct advantage for memory operation is the k value higher than 30 which is much higher than the amorphous counterpart and beneficial to reduce operation voltage since a higher effective electric field can be exerted on the tunnel SiO2 due to electric flux density continuity. The most concerned retention issue of adopting a crystalline high-k CTL has also be circumvented by passivation of grain boundaries related defects through plasma treatment. The concept of employing crystalline high-k dielectric as CTL not only works for Si-channel flash memory but also Ge-channel memory devices which enable superior memory performance to Si-based counterpart due to higher carrier mobility and more desirable band structure. For CTL based on crystalline oxide semiconductor, a CTL formed by stacking n-type and p-type oxide semiconductor demonstrates typical diode characteristics with a built-in internal electric field. It is the unique internal field that enhances P/E speed while reducing the operation voltage. Both kinds of CTL create a differentiating and pioneering technology that gains an outlook on realizing green flash memory devices.

No abstract

No abstract

Crystal growth of InP on GaAs by vapor phase epitaxy is reported. It is demonstrated that good quality InP epitaxial layers with featureless surface morphology can be grown on GaAs substrate. Carrier concentration profile and Hall mobility measurements from as-grown n-type InP layers show that its doping behavior and mobility are similar to those grown on InP substrates. The results are encouraging for the development of devices utilizing InP/GaAs heterojunctions and the use of bulk GaAs as an alternative substrate to bulk InP for the epitaxial growth of InP and related compounds.

No abstract

No abstract