This document provides information about a surface engineering course that discusses chemical vapor deposition (CVD) and the synthesis of nanomaterials. It explains that CVD is a bottom-up surface coating technique used to synthesize nanomaterials. It outlines the steps for preparing a substrate, which includes cleaning it with an emery sheet, ultrasonication, and acetone. The document then lists the 7-step procedure for the CVD process, which involves loading the cleaned substrate into a quartz tube, creating a vacuum, heating the substrate with argon gas, allowing the source gas like methane to deposit material, cooling with argon, and unloading the coated substrate.

1. Course code CME397 Course name Surface Engineering
Year/sem 3/6 Unit no 4
Course Instructor: M.Karthikeyan AP/Mech
Chemical vapour deposition (CVD)
 It is a surface coating technique.
 It is also used to synthesize/produce nanomaterials.
Nanomaterials can be synthesized in two ways
 Top-down approach
 Bottom-up approach
CVD comes under the category of bottom-up approach
Preparation of substrate
1. Initially the substrate should be cleaned with emery sheet to remove
any dust or foreign particles.
2. Then the substrate is cleaned using ultrasonication.
3. Finally, the substrate was cleaned with acetone and dried in air.
Procedure for CVD process
AAA COLLEGE OF ENGINEERING & TECHNOLOGY
Managed by Panjurajan – Amaravathy Trust and Promoted by Vinayaga- Sony Group of Industries
Accredited by NBA (CSE, ECE, EEE & MECHANICAL), (Accredited by NAAC with “A” grade)
(Approved by AICTE, New Delhi & Affiliated to Anna University, Chennai)
(An ISO 21001: 2018 Certified Institution)
Amathur, Sivakasi - 626 005.
Department of Mechanical Engineering

2. 1. Initially the substrate is loaded in the boat.
2. Then the boat is placed inside the quartz tube.
3. Now vacuum is crested to avoid the deposition of impurities.
4. Next argon gas is supplied to heat the substrate, just below the melting
point.
5. If once the temperature is reached, argon gas supply is switched off and
the source gas (example: methane CH4 is used to deposit graphene) is
allowed to pass for the required period.
6. After the deposition period, source gas supply is turned off and the
argon gas is allowed to pass for the purpose of cooling.
7. After the cooling process, the substrate can be unloaded from the quartz
tube and it can be used for further application.