EAGER: A novel approach to produce graphene for fabricating electronic devices

Tuskegee University, Tuskegee Institute AL

Investigators

Abstract

Title: A novel approach to produce graphene for fabricating electronic devices 1) Non-technical Abstract Decreasing the switching times is one of the most important requirements for enabling high performance electronic devices. In this regard, selecting advanced materials for such devices is vitally important. Graphene is a type of material with only one layer of carbon atoms packed in a honeycomb configuration. Since its discovery in 2004, graphene has shown many excellent properties, including a super high electron mobility, which means that the response time of electronic devices fabricated using graphene can be much shorter than on other materials. It is challenging, however, to produce large area and high quality graphene films prior to building such electronic devices. This project will try to develop a new method, low cost and easily set up, of growing graphene films. The idea is loading silicon carbide (SiC) into a high-temperature furnace with oxygen gas flowing through. SiC will be oxidized and a layer of silicon dioxide (SiO2) can be formed. Graphene films are expected to be grown between the SiC and SiO2. It has been shown that carbon atoms do exist between them. However, it is not yet reported that large area carbon atoms packed like honeycomb, i.e. graphene, are available. The goal of this project is to produce large area graphene films by trying different parameters during the growth. It is also proposed that graphene films with defined shapes can be grown. After graphene is produced, electronic devices will be fabricated on the grown graphene and their performance, such as response time, will be tested. If successful, the cost of electronic devices on graphene will be much lower. Since the project will be carried out at an HBCU school, underrepresented students will be encouraged to participate and they will be exposed to the frontier of graphene-based electronics. This project will also serve as a platform for many interdisciplinary students to learn semiconductor-related courses. 2) Technical Abstract This project aims to develop a new method for producing a 2-D carbon material: graphene. Current methods require either high temperatures (>1300oC) or high vacuum (<10-8 Torr). It is difficult for small research institutions to afford such type of facilities. The new method which is less costly, originates from the fact that carbon atom can accumulate between silicon carbide (SiC) and silicon dioxide (SiO2), reported by some groups, during the thermal oxidation process. Previous experiments conducted by the PI have also demonstrated that the channel mobility of lateral MOSFET on SiC sometimes is higher than its widely recognized values (160 cm2/V.s vs. 35 cm2/V.s), suggesting another mechanism may be involved. Smaller graphene flakes are suggested to be produced between SiC and SiO2 during the thermal oxidation process, a key step during the fabrication of MOSFETs. This project proposes to investigate whether the unusually high channel mobility is attributed to graphene. The idea is testing whether graphene flakes exist under the SiO2 layer of MOSFETs that show higher channel mobility. A correlation is expected to be built. More importantly, an attempt will be made to grow more uniform graphene films between SiC and SiO2 by adjusting the oxidation conditions such as temperature (900 ~ 1200oC), pressure (1 atm ~ 0.01 atm), flow rate, and oxidation time. Graphene films with defined shapes are also proposed to be produced with the help of ion-implantation. The goal is to develop a new graphene production approach which can be accomplished by most institutions and easily employed for fabricating electronic devices, particularly MOS devices and radio-frequency (RF) devices. Prototype of those devices will be demonstrated and measured. This project will have a great impact on graphene-based electronics, as well as other related fields.