Design and construction of microwave-PECVD and preliminary characteristics of synthesised polycrystalline diamond film / Nopporn Rujisamphan = การออกแบบและสร้างเครื่องไมโครเวฟ-พีอีซีวีดี และการใช้งานเบื้องต้นในการสังเคราะห์และตรวจสอบคุณสมบัติฟิล์มบางผลึกพหุเพชร / นพพร รุจิสัมพันธ์
We have designed and constructed a compact chemical vapor deposition using microwave plasma reactor. The system can be divided into two main parts; a vacuum chamber, and a power coupling modules. Aluminium rectangular waveguide WR340 was designed and constructed to guide the wave with TE10 mode. The brass antenna was used to convert the TE10 mode in WR340 waveguide into the TM011 mode in cylindrical resonator. Chemical vapor deposition diamond films have been successfully deposited on silicon substrates. At fixed pressure of 30 Torr, the well-faceted with lower full width at half maximum of diamond characteristic was found at low methane concentration (1%). At fixed methane concentration of 1% and deposition pressure of 10 Torr, we did not find diamond characteristic peak while at 30, 40, and 50 Torr, well-faceted films with good diamond characteristic were found. We found that the deposition at methane concentration of 1%, pressure of 30 Torr, microwave power of 450 watt, and substrate temperature of 430-470 C is the optimum condition in the range of our study yielding uniform film with distinct diamond characteristic.