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A Facile and Low-cost Process for Oxide Based Dielectrics and Semicondcutors and Transistors Therefrom

Summary

According to the International Technology Roadmap for Semiconductors, the introduction of a high-k material within the gate stack in complementary metal-oxide semiconductor (CMOS) baseline is mandatory in the near future for any kind of applications. Previous efforts in seek of high-k materials have been focused on metal oxides with a high permittivity such as TiO2, Ta2O5, In2O3, HfO2 and ZrO2. However, these metal oxides tend to have a narrow bandgap, which leads to a large leakage current. Meanwhile, various organic dielectric materials have been reported to show excellent dielectric property with a moderate leakage current when incorporated into thin film transistor devices. Nevertheless, the preparation of these dielectrics usually involves complicated steps and a certain number of chemicals, which are often non-environmentally friendly. And sometimes it is even worse, since the dielectric itself is toxic. Another drawback of these dielectric materials is their poor thermal stability at high temperature. Alumina has a dielectric constant almost twice of SiO2, and it has unique attributes such as non-toxicity, transparency, high ambient and thermal stability. The raw materials needed to fabricate it are abundant. However, due to its relatively small permittivity, alumina has often been ignored in previous studies to be used solely as the high-k dielectric. Although one has tried to prepare alumina dielectric by atomic layer deposition, magnetron sputtering and anodization, each of these methods suffers from either one or several of the following problems: low throughput, high cost, large leakage current, etc. The new technique invented here is a low-cost solution, which relies on the inexpensive equipment. The process is simple and involves a few starting chemicals. The throughput is high and appropriate for large area fabrication. The excellent and stable dielectric properties will ensure promising applications in low driving-voltage active electronic/photonic devices, which will immediately meet demands in reducing power consumption. It is environmentally friendly and completely safe to human beings. The nature of its transparency promises extended applications into future transparent electronics.

Application No.

10/ENG/381

Others

Inventor(s): Professor XU Jian Bin, Department of Electronic Engineering Patent Status: US Patent Pending Licensing Status: Available for licensing

Country/Region

Hong Kong