Optimization of hollow cathode discharge electrode for damage free remote plasma removal process for semiconductor manufacturing

Abstract

Cone-shaped hollow cathode electrode configuration for a damage free remote plasma removal process has been optimized for given pressures based on Paschen characteristic curves, voltage–current characteristics and time-resolved discharge observations as well as oxide film removal performances. Remote plasmas have been generated in two types of cone-shaped electrodes with mixtures of He, NF3, and NH3 for pressure range of 1–30 Torr. Paschen characteristic curves and voltage–current (V–I) characteristics define an operating pressure for low breakdown voltage and the hollow cathode effect to minimize the particles. Sinusoidal voltage waveform and asymmetry electrode configuration alternate the glow discharge and hollow cathode discharge modes in a cycle. The current and infrared emission intensity from the glow discharge increases together for both cone-shaped electrodes with increasing pressure, whereas the hollow cathode discharge plasma emits strong infrared only when pD condition is satisfied. For the wide cone electrode configuration, high voltage operation at higher pressure results in particle contamination on the processed wafer by high energy ion bombardment. Operating at optimum pressure for a given electrode configuration shows faster oxide etch rate with better uniformity over a whole 300 mm wafer.

Influence of cold hollow cathode geometry on the radial characteristics of downstream magnetized plasma column

“…The observed discharge characteristics in figure 4 are in agreement with earlier experimental reports, which showed higher ionization and power deposition inside conical cathode than a cylindrical cathode system [5][6][7]. The frontal and the lateral images of the plasma column from each HC setup is shown in figure 4(c).…”

“…, where ν iz is the frequency of ionization. Considering that ions are un-magnetized in the system, the ion momentum equation reduces to equation (6), where M is the ion mass, e is the electron charge and E is the local electric field inside the plasma volume. The radial component of this electric field can be derived from the plasma potential f by = -…”

“…The electrostatic trapping of these energetic electrons between the opposing cathode sheaths helps to operate such hollow cathode (HC) devices at low neutral gas pressure. In the past several variants of cathode geometries have been used to improve the discharge efficiency [2,[4][5][6][7][8][9][10][11][12]. Additionally, a transverse magnetic field can dramatically influence the discharge properties of HC plasma sources as reported in [13][14][15][16][17][18][19].…”

Utilizing an α,β-Unsaturated Dicarboxylic Acid for a Defect Initiated Residue Removal During Cu post-Chemical Mechanical Planarization Cleaning

“…The addition of a corrosion inhibitor ( i.e., BTA) controls the static dissolution via the formation of complexes that modulate the rate of oxidation from Cu(0) to Cu(I) to Cu(II). 13,31,32 Commonly, the incorporation of BTA will form a polymeric film via Cu(I) coordination on the surface of a Cu substrate resulting in an interactive but dense passivation film. 33 It has been reported that the BTA film forms in a two-stage process consisting of BTA surface adsorption and subsequent complexation with the oxidized Cu(I) species (logβ = 1.54 × 10 −2 ) at the interface.…”

Progress and prospects in nanoscale dry processes: How can we control atomic layer reactions?

“…A (NH 4 ) 2 SiF 6 -based modified layer forms on the surface of SiO 2 when it is exposed to etchants such as NH 3 =NF 3 -based or HF=NH 3based chemistry. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33] These chemistries were commercialized in the semiconductor industry for use in precleaning technologies in film deposition, silicidation, and the fabrication of high-k dielectric metal gates. [29][30][31][32][33] Very recently, the thermal cyclic etching of SiN has also been realized.…”