Fabrication of plasma probe for chemical vapor deposition

An atmospheric pressure low-power, capacitively coupled RF plasma probe was designed and fabricated for selective-area chemical vapor deposition of materials at room temperature. The probe consisted of a gas channel with two electrodes forming a capacitor through the gas and channel wall. An inductor was used to match the capacitive electrodes to 50 Ω RF source at 600 MHz. The resulting LC circuit along with the plasma formed a second order system with a stable resonance near 600 MHz. Ge, Si, Si_1-xGe_x and Ni were respectively deposited using SiH₄, GeH₄, and nickelocene on various substrates including microscope glass slide, gold, p- and n-type Si, SiO₂ and Si₃N₄. SEM, AFM and EDX studies were used to study the deposited materials. Similar approach was then adopted to generate plasma between conducting AFM tip and a substrate to deposit and pattern materials at 10-500 nm scale.