A study of anisotropic trench etching of Si with NF3–halocarbon

Abstract

Articles you may be interested inSmoothing single-crystalline SiC surfaces by reactive ion etching using pure NF3 and NF3/Ar mixture gas plasmas J. Vac. Sci. Technol. A 32, 051303 (2014); 10.1116/1.4893421Water vapor controlling selective reactive ion etching of SiO2/Si in NF3 plasma Plasma etching ofSi was carried out with a parallel plate, radial flow, 13.56 MHz plasma etcher. The formation of a polymer film has been promoted by adding a controlled amount of halocarbon to NF3< The polymer film acts as a sidewall barrier film. As a result, the undercutting usually observed in the etch profile has been eliminated or minimized. The deposition ofthe polymer film depends on the chemistry and concentration of halocarbon. Etch rates ranging from 0.4 to 0.6 l.tm/min have been obtained.

Rf discharge dissociative mode in NF3and SiH4

“…Rf discharge in NF 3 is widely used for cleaning technological chambers [1][2][3][4][5][6], etching silicon-containing materials [7][8][9][10][11][12][13][14][15][16] and plasma treatment of polymeric dielectrics [17]. This gas is of interest due to the following reasons.…”

Langmuir Probe Measurements and Characterization of Silicon Etching in SF 6 / O 2 Discharges

“…The main source of oxygen, incorporated in the melt during CZ crystal growth, is the silica crucible. The oxygen fluxes in the melt have been analyzed theoretically (1), and the oxygen transport from the crucible to the melt have been studied by the present authors (2). It was concluded that cristobalite partly forms along the interface between liquid silicon and a silica crucible.…”

“…The increase in the F atom concentration and the decrease in SF6 concentration are both moderate while the concentration of SO2F2 increases significantly. It can be concluded, therefore, that the main effect of increasing pressure is to enhance the oxyfluoride production rates, thus reducing the recombination reactions [1].…”

“…High fluorine signal could also result from accumulation of F atoms in the ionizing chamber of the mass spectrometer. The concentrations of SF6 and SF4 decrease with increasing oxygen content, due to the lower recombination rates (reaction [1]).…”

“…Among the various gases used for plasma processing of semiconductor materials, sulfur hexafluoride possesses several advantages over chlorine and bromine containing gases, such as higher etching rate, lower corrosivity and toxicity, and no polymer deposition on the wafer (1,2). Due to the high reactivity between F atoms and silicon, however, the degree of anisotropy is usually low, as in other fluorine containing gases, such as CF4 and NF3.…”