Particulate generation in silane/ammonia rf discharges

Abstract

The rate of particle generation in a SiH4/NH3 rf discharge has been studied as a function of the discharge operating parameter space, electrode geometry, and power supply coupling mode. Measurements of the bulk quantity of particles produced in the discharge reveal that the mode of coupling (capacitive or dc) as well as the electrode temperature significantly affects particle generation rates. Laser light scattering measurements made as a function of the plasma power density indicate that particle generation abruptly ceases at a threshold value sufficient to induce spark breakdown at the cathode. Based on these observations, it is shown that particle growth in plasmas can be modeled entirely as a heterogeneous process. The initiation of particle growth is shown to be consistent with an electron surface desorption model involving vibrational excitation of surface clusters. Propagation of growth in the gas phase is shown to be consistent with an eliminative ion-molecular condensation reaction, and the pressure dependence of this mechanism is exploited to estimate a value for the rate constants for SiH4 and NH3 condensation in SiN:H particle growth.

Dusty Plasma Studies in the Gaseous Electronics Conference Reference Cell

“…Process-induced particles often grow by a cluster interaction or coagulation process [15], followed by a more open agglomeration of primary particles [16]. Coagulation and agglomeration are the processes which make possible the very rapid growth of particles to sizes visible by LLS noted in this study.…”

“…4 from the particle trap region shows the trap is densely populated with particles. Numerous pervious studies [10,16] have shown particle densities under such conditions reach 10 6 /cm 3 to 10 8 /cm 3 .…”

Modeling of the formation of cationic silicon clusters in a remote Ar/H2/SiH4 plasma

“…The formation and growth process of negative ionic clusters is a widely studied topic, [5][6][7] and so is the formation of dust. [8][9][10][11][12][13][14] However, the formation of large positive silicon clusters is less known. In radio-frequency ͑rf͒ plasmas, their presence is not likely since they are not confined by the electric field.…”

Observation of the trajectories of particles in process equipment by an in situ monitoring system using a laser light scattering method

“…[1][2][3][4][5][6][7][8][9][10][11] However, these studies were based on single wafers and they described the motion of particle clouds, but they did not accurately reflect manufacturing conditions.…”