Development of a new direct liquid injection system for nanoparticle deposition by chemical vapor deposition using nanoparticle solutions

Abstract

Nanoparticles of different materials are already in use for many applications. In some applications, these nanoparticles need to be deposited on a substrate in a fast and reproducible way. We have developed a new direct liquid injection system for nanoparticle deposition by chemical vapor deposition using a liquid nanoparticle precursor. The system was designed to deposit nanoparticles in a controlled and reproducible way by using two direct liquid injectors to deliver nanoparticles to the system. The nanoparticle solution is first evaporated and then the nanoparticles flow onto a substrate inside the vacuum chamber. To allow injection and evaporation of the liquid, a direct liquid injection and vaporization system are mounted on top of the process chamber. The deposition of the nanoparticles is controlled by parameters such as deposition temperature, partial pressure of the gases, and flow rate of the nanoparticle suspension. The concentration of the deposited nanoparticles can be varied simply by changing the flow rate and deposition time. We demonstrate the capabilities of this system using gold nanoparticles. The selected suspension flow rates were varied between 0.25 and 1 g/min. AFM analysis of the deposited samples showed that the aggregation of gold nanoparticles is well controlled by the flow and deposition parameters.

A Novel Direct Liquid Injection Low Pressure Chemical Vapor Deposition System (DLI‐LPCVD) for the Deposition of Thin Films

“…[18] Together with the general applicability of CVD, this approach could be easily integrated into the design of useful products and devices. LPCVD was chosen to decrease unwanted gas phase reactions and increase the uniformity across the substrate.…”

“…[23,24] At highT : SiðOC2H5Þ4 ! [18] The different samples with their deposition characteristics and resulting thicknesses calculated by X-ray reflectivity (XRR) and Spectroscopic Ellipsometry (SE) are given in Table 1. It is to be noted that in TEOS the silicon atom is already oxidized and the conversion of TEOS to silicon dioxide is essentially a rearrangement of the molecular structure.…”

“…This reaction at the surface is what causes the formation of solid phase material on the substrate. [18] Together with the general applicability of CVD, this approach could be easily integrated into the design of useful products and devices. A DLI-LPCVD process is performed thanks to the use of a Direct Liquid Injection (DLI) vaporizer.…”

Direct Liquid Injection − Low Pressure Chemical Vapor Deposition of Silica Thin Films from Di‐t‐butoxydiacetoxysilane

“…Changing the amount of added oxygen gives the ability to change the refractive index, roughness, composition, and hydrophilicity of the films. Working with a solution of DADBS makes embedding of nanoparticles possible opening a lot of (new) opportunities . Therefore, a big advantage of the presented technique is the wide range of films that can be produced by varying the precursors.…”

“…The use of a solution instead of pure DADBS, as well as direct liquid injection (DLI) approach, however, is not described before, and could be advantageous as a better control of the DADBS vapor delivery to the process and a lower deposition rate can be achieved. Moreover, it gives the ability to change concentrations as extra parameter and makes embedding of nanoparticles possible, opening a lot of (new) opportunities . Interest arises from the wide range of functionalities that the films can possess such as optical, catalytic, electrical, and thermal functionalities; all largely determined by the composition, size, morphology, and surface properties of the NPs forming the film.…”