Modeling the Carrier Mobility in Nanowire Channel FET
- PDF / 379,941 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 75 Downloads / 174 Views
1017-DD14-06
Modeling the Carrier Mobility in Nanowire Channel FET Werner Prost1, Kai Blekker1, Quoc-Thai Do1, Ingo Regolin1, Sven M¸ller2, Daniel Stichtenoth2, Katharina Wegener2, Carsten Ronning2, and Franz-Josef Tegude1 1 University Duisburg-Essen, Lotharstr. 55, Duisburg, 47057, Germany 2 University of Gˆttingen, Friedrich-Hund-Platz 1, Gˆttingen, 37077, Germany
ABSTRACT We report on the extraction of carrier type, and mobility in semiconductor nanowires by adopting experimental nanowire field-effect transistor device data to a long channel metalinsulator-semiconductor field-effect transistor device model. Numerous field-effect transistors were fabricated using n-InAs nanowires of a diameter of 50 nm as a channel. The I-V data of devices were analyzed at low to medium drain current in order to reduce the effect of extrinsic resistances. The gate capacitance is determined by an electro-static field simulation tool. The carrier mobility remains as the only parameter to fit experimental to modeled device data. The electron mobility in n-InAs nanowires is evaluated to µ = 13,000 cm≤/Vs while for comparison nZnO nanowires exhibit a mobility of 800 cm≤/Vs. INTRODUCTION Semiconductor nanowires (NW) are one dimensional wires, or columns of materials that may grow in an epitaxy based bottom-up process using i. e. the vapor-liquid-solid (VLS) growth mode [1]. The VLS growth is a vapor transport technique which may be realized in a tube furnace or in a metal organic vapor phase epitaxy (MOVPE). Recently, this approach has demonstrated its potential as a key building block for future electronic and optoelectronic nanoscaled devices. First demonstrations of nanowire field-effect transistor (FET) based on InAs [2], ZnO [3-4], Ge [5] and many other materials have been reported. However, the determination of transport data is a difficult task for any nanowire. The contact and wire resistance can both be determined by applying transmission line type measurements [6]. The extraction of the carrier mobility from experimental I-V characteristics of a NW FET is carried out under the assumption of a constant geometrical gate capacitance implemented in a long channel metal-insulatorsemiconductor field-effect transistor (MISFET) model [5]. In this work, the validity of the model will be analyzed using a variety of isolation layer thickness and gate length. A new top gate capacitance model is developed and will be used to evaluate the mobility present in an InAs nanowire FET. Finally, the method is adopted to selected ZnO nanowire FET devices. EXPERIMENT InAs nanowires were grown in an MOVPE apparatus at a growth temperature of 400 ∞C for 10 minutes [6]. Prior to growth colloidal Au nanoparticles of 50 nm diameter were deposited on the InAs (100) substrate surface as seed particles. The main growth direction is (100) but growth in various (111) directions is also observed. Single crystalline zinc oxide (ZnO) nanowires were synthesized in a horizontal tube furnace in the VLS growth mode using high-
purity ZnO powder as source materia
Data Loading...
