An E ⃗×B ⃗ plasma is important for various applications including Hall thrusters and magnetic nozzle for long-lasting space propulsion. Such a cross field arrangement in inductively coupled plasma plays vital role in film deposition and etching that are the basic ingredients in semiconductor industries; though in these applications, only the electrons are magnetized which enhance the plasma production and hence, ultimately control the etching aspect ratio and film quality. In the present work, an E ⃗×B ⃗ plasma is considered where ionization takes place and finite temperature gradient also exists. Specifically, a theoretical model is developed for analysing the effect of magnetic field on the density gradient driven instability. The growth rate of the instability is evaluated as a function of plasma background density, scale length of density gradient, ionization frequency, charge on ions, ion temperature gradient, temperatures of plasma species and magnetic field. To generalize the situation, case of different masses of the ions is also reviewed by considering both the electrons and the ions to be magnetized. Manuscript profile

Plasma-material interaction has been a subject of interest for the past several decades due to its importance in various fields of research such as film deposition, surface nitriding, plasma etching, plasma reactors at low-pressure conditions etc. During this interaction, the presence of negative ions further plays a vital role to ease defect-free analysis of soft substrates. The response of plasma through the sheath formation, when a metallic plate or probe is inserted into it, depends on the plasma characteristics / parameters and the bias voltage used on the plate or probe. The Bohm’s criterion decides such kind of interaction. The present work theoretically demonstrates a modified Bohm’s criterion in an electronegative plasma which is collisional and has two-temperature non-extensive electrons (hot and cold electrons). The behaviour of positive ions is considered through their fluid equations, whereas the negative ions are taken to follow Boltzmann distribution. While writing the basic equations, ion source term and ionization rate are retained and Sagdeev’s potential approach is employed to evaluate the Bohm’s criterion which reveals a band for the positive ion velocity, means maximum and minimum values for the ion velocity. This modified Bohm’s criterion is studied under the effects of various plasma parameters. Manuscript profile