Detection of particles in rf silane plasmas using photoemission method

Abstract

Nucleation and subsequent initial growth processes of particles in rf silane plasmas are investigated using a newly developed photoemission method. In this method, electrons produced due to interactions of particles with photons (photodetachment, photoionization) are measured. Since threshold energies for the interactions are dependent on particle size, size ranges of the detected particles are determined by wavelengths of the irradiated light. Using this method, small particles such as SinHx (n≲10), SinHx (n≲200) and SinHx (n≳20) can be detected. The experiments show that even in a very early phase of their growth, particles nucleate and grow principally around the plasma/sheath boundary near the rf electrode, where short lifetime radicals are produced actively. This suggests that the short lifetime radicals are the key species contributing to the particle nucleation and its subsequent initial growth processes. Moreover, it is found that small particles exist even in the bulk plasma. Since some of them are considered to be neutral, they are likely to be transported to the substrate on the grounded electrode.

Fabrication of dense yttrium oxyfluoride ceramics by hot pressing and their mechanical, thermal, and electrical properties

“…In particular, particle contamination generated by plasma in manufacturing processes such as dry etching has become a big problem. [4][5][6][7][8][9][10][11][12][13] As the ICs size decrease, fewer and smaller particle defects are acceptable during the plasma process in semiconductor production. Plasma-resistant materials such as Si, SiC, and WSi are required to prevent the formation of particle defects.…”

Micro-Disperse Particles in Plasmas: From Disturbing Side Effects to New Applications

“…Typical examples are plasma polymerization [33] and thin film deposition in silane-containing Plasma Enhanced Chemical Vapour Deposition (PECVD) processes [33,34]. The different stages of the particle growth in the gas phase can be observed by mass spectrometry [13], laser induced evaporation [35] photo-detachment [34], [36], IR absorption [37], microwave cavity measurements [34], Mie scattering [38], and Self Excited Electron Resonance Spectroscopy (SEERS) [7,39]. The generated particles can be analyzed by transmission electron microscopy (TEM).…”

“…• driven particle oscillation about equilibrium by superposition of an external lowfrequency voltage [71], • laser-induced photodetachment of charge and subsequent detection by microwave interference methods [34] or probes [36] • formation of Mach cones by moving dust particles [72],…”

Study on growth processes of particles in germane radio frequency discharges using laser light scattering and scanning electron microscopic methods

“…[11][12][13][14][15][16][17][18][19][20] Si particles grow through three characteristic phases of initial growth including nucleation, rapid growth, and growth saturation. In the initial growth phase, they are nucleated and grow up to about 10 nm in size, principally around the plasma/sheath boundary near the powered electrode, where densities of highly reactive species such as Si and SiH 2 are the highest.…”