Etching is one of the most commonly used methods for creation of investigated micro- and nanostructures in different fields, and especially in nanoelectronics. Today, one of the most widely used etching methods is dry etching. The main benefits of this type of etching are processing at low temperature, easy control of etching rates, and high flexibility in creation of fine structures (such as determining isotropic or anisotropic etching, only by selecting and controlling the etchant gases).
Reactive ion etching (RIE) is one of the most widely used plasma etching method. Dry etching based on RIE technique, i.e. creation of reactive ions by RF plasma and bombardment of the sample, is carried out through the simultaneous physical and chemical etching.
Etching of materials such as Si, SiO2 and Si3N4 for fabrication of nanowires and nanopores (as active layer in photodetectors, gas nanosensors, photonic crystal devices, light sources, AFM tip, etc.), and microelectromechanical systems (such as accelerometers, pressure gauges, gyroscopes, etc.) is possible using this instrument.
In this method, the patterned samples with micrometer or nanometer scale structures are placed into the RIE device, and then are etched using free radicals that are generated via the activation of desired gas by RF plasma.
Silicon Deep Reactive Ion Etching (DRIE) system is one of the most commonly used devices in electronics FAB and micro/ nanoelectronics labs, by which dry etching of silicon is performed. The unique feature of this device is its designed process which uses low-cost gases such as hydrogen, oxygen, and SF6.
The system includes vacuum chamber, mechanical and roots vacuum pumps, RF power supply with frequency of 13.56 MHz, impedance matching system for different types of gases, input gas flow controller (MFC), digital program as well as fully automatic controller. The record of deep etching onto the silicon substrate using this device is 150 μm.
The main input gases for plasma generation are hydrogen, oxygen, and SF6; and the minimum pressure is 0.0001 Torr. This device is capable of conducting anisotropic and vertical etching onto the plastic and silicon substrates. Furthermore, etching services for removing lithographic residues, as well as surface functionalization (hydrophobicity, hydrophilicity, dyeability, etc.) can be carried out by this device. Fabrication of MEMS and NEMS systems, sensors, accelerometers, and suspended structures like cantilevers will be possible with this device. The software features of this device are as follows:
· Possibility to choose the number of stages in a cycle
· Possibility to choose and adjust the flow of required gas in each stage
· Possibility to adjust RF power in each stage
· Ability to choose the number of cycles during a process
· Ability to use default settings