Optical emission spectroscopic investigation of hydrogen plasma used for modification of electrical properties of multi-crystalline silicon

Abstract

Results of the treatment of multi-crystalline silicon with low-pressure inductive plasma are presented. Plasma treatment was found to increase silicon electrical conductivity to a greater value relative to its initial state; the time to reach this maximum was found to depend strongly on temperature between 120 and 400 °C. An effect of plasma parameters on collection efficiency and diffusion length was observed by EBIC measurements. An actinometry method based on optical emission spectroscopy measurements was used to determine the molar fraction of monatomic hydrogen produced in plasma in the range between 5% and 8% during the treatment. The excitation temperature calculated by Boltzmann's method ranged between 4500 and 8000 K depending on the plasma gas composition, the pressure and the applied power. A model was developed using the CHEMKIN III® software to compute the role of operational parameters in hydrogen–silicon interactions. The aim of this work is to elucidate the relation between the plasma characteristics and the efficiency of hydrogen passivation on multi-crystalline silicon.

Metal Al Produced by H2 Plasma Reduction of AlCl3: A Thermodynamic and Kinetic Study on the Plasma Chemistry

“…Using well established transition probability values of H atoms 28 and plotting I jfk λ jk /A jk g j against E j -E k , T e can be obtained. 29 The statistic weight of the higher energy levels of H R , H β , and H γ are 18, 32, and 50, corresponding to the principle quantum number 3, 4, and 5, respectively. The results were plotted in Figure 4b, showing a slight decrease with increasing Ar.…”

Atmospheric Plasma Treatment Enhances the Biosensing Properties of Graphene Oxide-Silver Nanoparticle Composite

“…26,27 For the optical emission spectra (OES) of Ar plasma, the intense lines corresponding to Ar are observed in the range of 700nm to 800nm and Hydrogen species are at 410.2nm, 434nm and 656.5nm. 28 The presence of excited species in the cold atmospheric Ar plasma contributed to the deoxygenation of GO. When the GO deposited samples interacts with the ions, radicals and neutral molecules present in the plasma, deoxygenation starts.…”

Ultra high amorphous silicon passivation quality of crystalline silicon surface using in-situ post-deposition treatments

“…We notice a progressive increase of the emission intensities of H α * with rising plasma power density and decreasing working pressure. Higher plasma power densities lead to an increase in the electronic temperature, favoring the excitation and then the dissociation of monatomic hydrogen . While at low pressures the energy of electrons is sufficient for H atom excitation leading to higher hydrogen emission intensity with high excitation temperatures .…”

“…Higher plasma power densities lead to an increase in the electronic temperature, favoring the excitation and then the dissociation of monatomic hydrogen . While at low pressures the energy of electrons is sufficient for H atom excitation leading to higher hydrogen emission intensity with high excitation temperatures . The reason for the reduction of the emission intensities at high pressures is that the molar fraction of atomic hydrogen drops and the recombination processes such as three‐body recombina‐ tion (H + + e + e → H* + e), dissociative recombination (H 2 + + e → H* + H), and mutual neutralization (H + + H – → H* + H) can be produced between atomic hydrogen and its excited state .…”

“…While at low pressures the energy of electrons is sufficient for H atom excitation leading to higher hydrogen emission intensity with high excitation temperatures . The reason for the reduction of the emission intensities at high pressures is that the molar fraction of atomic hydrogen drops and the recombination processes such as three‐body recombina‐ tion (H + + e + e → H* + e), dissociative recombination (H 2 + + e → H* + H), and mutual neutralization (H + + H – → H* + H) can be produced between atomic hydrogen and its excited state . However, higher working pressure results in better drift and diffusion phenomenon of dissociated hydrogen into the bulk of intrinsic a‐Si:H layer .…”