Probing C84-embedded Si Substrate Using Scanning Probe Microscopy and Molecular Dynamics

Summary

This paper reports the nanomaterial fabrication of a fullerene Si substrate inspected and verified by nanomeasurements and molecular dynamic simulation.

Abstract

This paper reports an array-designed C₈₄-embedded Si substrate fabricated using a controlled self-assembly method in an ultra-high vacuum chamber. The characteristics of the C₈₄-embedded Si surface, such as atomic resolution topography, local electronic density of states, band gap energy, field emission properties, nanomechanical stiffness, and surface magnetism, were examined using a variety of surface analysis techniques under ultra, high vacuum (UHV) conditions as well as in an atmospheric system. Experimental results demonstrate the high uniformity of the C₈₄-embedded Si surface fabricated using a controlled self-assembly nanotechnology mechanism, represents an important development in the application of field emission display (FED), optoelectronic device fabrication, MEMS cutting tools, and in efforts to find a suitable replacement for carbide semiconductors. Molecular dynamics (MD) method with semi-empirical potential can be used to study the nanoindentation of C₈₄-embedded Si substrate. A detailed description for performing MD simulation is presented here. Details for a comprehensive study on mechanical analysis of MD simulation such as indentation force, Young's modulus, surface stiffness, atomic stress, and atomic strain are included. The atomic stress and von-Mises strain distributions of the indentation model can be calculated to monitor deformation mechanism with time evaluation in atomistic level.

Introduction

Fullerene molecules and the composite materials they comprise are distinctive among nanomaterials due to their excellent structural characteristics, electronic conductivity, mechanical strength, and chemical properties^1-4. These materials have proven highly beneficial in a range of fields, such as electronics, computers, fuel cell technology, solar cells, and field emission technology^5,6.

Among these materials, silicon carbide (SiC) nanoparticle composites have received particular attention thanks to their wide band gap, high thermal conductivity and stability, high electrical breakdown ability, and chemical inertness.....

Protocol

NOTE: The paper outlines the methods used in the formation of a self-assembled fullerene array on the surface of a semiconducting substrate. Specifically, we present a novel method for the preparation of a fullerene-embedded silicon substrate for use as a field emitter or substrate in microelectromechanical systems (MEMS), and optoelectronic devices in high-temperature, high-power, applications as well as in high-frequency devices^9-13.

1. Fabrication of Hexagonal-closed-packaged (HCP) Overlayer of C₈₄ on Si Substrate

1. Prepare Clean Si(111) Substrate
   1. Subject Si substrate to RCA (Radio Corporation ....

Results

A monolayer of C₈₄ molecules on a disordered Si(111) surface was fabricated using a controlled self-assembly process in a UHV chamber. Figure 1 shows a series of topographic images measured by UHV-STM with various degrees of coverage: (a) 0.01 ML, (b) 0.2 ML, (c) 0.7 ML, and (d) 0.9 ML. The electronic and optical properties of the C₈₄ embedded Si substrate were also investigated using a variety of surface analysis techniques, such as STM and PL (Figure 2). The excel.......

Discussion

In this study, we demonstrate the fabrication of a self-assembled monolayer of C₈₄ on a Si substrate through a novel annealing process (Figure 1). This process can also be used to prepare other kinds of nanoparticle-embedded semiconductor substrates. The C₈₄-embedded Si substrate was characterized at the atomic scale using UHV-STM (Figure 2), field emission spectrometer, photo-luminescence spectroscopy, MFM and SQUID (Figure 3).

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Silicon wafer			Si(111). Type/Dopant: P/Boron; Resistivity: 0.05-0.1 Ohm·cm
Carbon, C84	Legend Star		C84 powder, 98%
Hydrochloric acid	Sigma-Aldrich	84422	RCA, 37%
Ammonium	Choneye Pure Chemical		RCA, 25%
Hydrogen peroxide	Choneye Pure Chemical		RCA, 35%
Nitrogen	Ni Ni Air		high-pressure bottle, 95%
Tungsten	Nilaco	461327	wire, diameter 0.3 mm, tip
Sodium hydroxide	UCW	85765	etching Tungsten wire for tip
Acetone	Marcon Fine Chemicals	99920	suitable for liquid chromatography and UV-spectrophotometry
Methanol	Marcon Fine Chemicals	64837	suitable for liquid chromatography and UV-spectrophotometry
UHV-SPM	JEOL Ltd	JSPM-4500A	Ultrahigh Vacuum Scanning Tunneling Microscope and Ultrahigh Vacuum Atomic Force Microscope
Power supply	Keithley	237	High-Voltage Source-Measure Unit
SQUID	Quantum desigh	MPMS-7	Magnetic field strength: ±7.0 Tesla, Temperature range: 2–400 K, Magnetic-dipole range: 5 × 10-7 – 300 emu
ALPS	National Center for High-performance Computing, Taiwan		Advanced Large-scale Parallel Supercluster, 177Tflops; 25,600 CPU cores; 73,728 GB RAM; 1,074 TB storage