The Study On Deposition And Properties Of DLC/ZnO/Si, DLC/ZnO/Diamond Multiple Films For SAW Sensor

Due to hundreds of lives had been lost by gas poisoning, it is important to establish a secure system of realtime detecting gas continuously in our working or living environment. Surface acoustic wave (SAW) gas sensor is consider as a new sensor with its outstanding virtue of higher sensitivity, faster responsivity, smaller volume, lower cost and easier taking. Some of them have highest sensitivity without sensing film. But, it is desponding that SAW gas sensor without sensing film is influenced by vapour easily in atmosphere. So the responsivity declined and noise had been created.Diamond-like Carbon (DLC) films process excellent properties such as high hardness, high resistance, high diathermaneity, low coefficient of friction and unique chemical stability. It also could protect SAW sensor with its characteristic of refusing water molecule and enhance the detecting precision. In addition, DLC films could be deposited at high speed in low temperature. So it is a best choice that DLC films is used in the realm of SAW gas sensor.In this paper, DLC films had been deposited by by Magnetoactive - Radio Frequency - Plasma Enhanced Chemical Vapor Deposition (M-RF-PECVD) method. Our work had been listed.1. Diamond-like carbon films were made on glass substrates and Si (100) substrates in room temperature. The film characteristics were investigated using fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and scanning electron microscope (SEM). The research results show that hydrogenated carbon films which prepared at power of 50W, pressure in 30Pa and CH4/Ar ratio at 5/90 have a smooth surface and were composited by sp3 amorphous carbon mostly.2. ZnO films had been prepared by using RF magnetron sputtering method on Si and Diamond substrate respectively first. And then, DLC films had been deposited on the structure of ZnO/Si and ZnO/Diamond respectively. Each film Surface morphology were investigated by SEM. The result show that combination of each film is good.3. DLC films had been deposited on unpolished diamond substrate 4 hours. The result indicate that growth side is too rough to be covered with DLC smoothly. But the contacting side of unpolished diamond had been improved slightly.In conclusion, We investigated deposition of DLC films by M-RF-PECVD primarily and explored multilayer structure of DLC/ZnO/Si, DLC/ZnO/Diamond and DLC/Diamond. We had got useful data for DLC deposition in low temperature and SAW gas sensors without sensing film.