China 
Africa 
Explore chapters and articles related to this topic
Nanosensor Laboratory
Published in Vinod Kumar Khanna, Nanosensors, 2021
Can etching be done without liquid etchants? Yes, reactive-ion etching (RIE) is a process that uses dry chemical and physical processes to etch away desired materials. What is the essence of RIE? In RIE, the substrate is placed inside a reactor, in which a mixture of gases is introduced (Figure 3.13). A plasma (a gas of positive ions and free electrons containing approximately equal positive and negative charges) is struck in the gas mixture, using an RF (radio frequency) power source, breaking the gas molecules into ions. The ions are accelerated toward and react at the surface of the material being etched, forming another gaseous material. This is known as the chemical part of RIE. There is also a physical part, that is similar in nature to the sputtering deposition process. If the ions have sufficiently high energy, they can knock atoms out of the material to be etched without a chemical reaction. This dislodging of atoms by impact or collision constitutes the physical part of the etching. Synergy between the chemical reaction and ion bombardment leads to high etch rates. Transformer-coupled plasma RIE system.
Fabrication of BioMEMS Devices
Published in Simona Badilescu, Muthukumaran Packirisamy, BioMEMS, 2016
Simona Badilescu, Muthukumaran Packirisamy
Dry etching, which uses gases for etching, is suitable for making very small features in thin films, and it is used when a high resolution is necessary. There are many classes of dry etching techniques called high-pressure plasma etching, reactive ion etching (RIE), deep reactive ion etching (DRIE), and ion milling. In high-pressure plasma etching, the reactive species that are created react with the material to be etched, and as a result, the material is dissolved at the surface. In the RIE technique, the material to be etched is introduced in a reactor where a plasma is formed by using an RF power source (Figure 7.10). The high-energy ions may either hit the material and remove atoms from the surface or react at the surface of the material. Because there are many more collisions with the horizontal surfaces than with the walls, the etching rate will be higher.
Micro-Manufacturing Processes for Gas Sensors
Published in Ankur Gupta, Mahesh Kumar, Rajeev Kumar Singh, Shantanu Bhattacharya, Gas Sensors, 2023
Pankaj Singh Chauhan, Shantanu Bhattacharya, Aditya Choudhary, Kanika Saxena
Etching is a material removal technique which can be used in micro-fabrication of MEMS devices [44]. There are two types of etching methods, wet and dry. Etching by wet method utilizes a chemical solution and dry method utilizes a gas phase chemistry to remove the material. Etching can be isotropic, if the etch rate is the same in all directions or anisotropic, if the etch rate is different for different directions [42]. A specific etchant is used for every material to be etched. Wet etching process is generally isotropic and dry etching is anisotropic in nature. Reactive ion etching (RIE) is a type of dry etching where a gas plasma is used to clean the substrate. In RIE, the ions from plasma attack the substrate surface and react with it.
Substrate-morphology driven tunable nanoscale artificial synapse
Published in Journal of Asian Ceramic Societies, 2021
Shahid Iqbal, Mohit Kumar, Ranveer Singh, Qadeer Akbar Sial, Hyungtak Seo
The RIE is a plasma process for etching materials by radio frequency (RF) gas discharges (ions, radicals) in a low-pressure chamber. It is a collaborative process between energetic ion bombardment and chemically active species. On the other hand, several conditions were applied in an attempt to engineer nanostructures of the surface of substrate at required nanoscale level. After all, the working pressure was kept at 150 mTorr with 50 W of power. SF6 gas pressure was kept fixed at 20 sccm for 30 and 60 s, separately.