Auto capacitance tuner current compensation to control one or more film properties through target life

Abstract

In some embodiments a method of depositing a metal-containing layer atop a substrate disposed in a physical vapor deposition (PVD) chamber includes: providing a plasma forming gas to a processing region of the PVD chamber; providing a first amount of RF power to a target assembly disposed opposite the substrate to form a plasma within the processing region of the PVD chamber; sputtering source material from the target assembly to deposit a metal-containing layer onto the substrate, wherein the source material is at a first erosion state; and tuning an auto capacitance tuner coupled to a substrate support while sputtering source material to maintain an ion energy at a surface of the substrate within a predetermined range as the target erodes from the first erosion state to a second erosion state.

Description

technical field [0001] Embodiments of the present disclosure generally relate to substrate processing systems. Background technique [0002] Use high-density, low-stress films suitable for back-end-of-line (BEOL) hardmask applications, such as titanium nitride (TiN) films, to reduce the dielectric (low-k dielectric) trenches used in patterning low-k dielectrics Line bending of trenches and improved low-k etch profile by reducing line edge roughness and critical dimension (CD) variation. [0003] Radio frequency (RF) power can be supplied to the primary DC plasma to increase the ionization rate of sputtered material in the plasma. The increased ionization rate allows improved surface mobility to atoms, resulting in crystalline film orientation, which facilitates low stress and dense films. In addition, the high proportion of ionizing material reaching the substrate level allows modulation of the incoming ion energy in the manner of the wafer susceptor impedance circuit. ...

AI Technical Summary

Problems solved by technology

[0005] One disadvantage of supplying RF power to the target in combination with magnetic confinement at the target surface is that the efficiency of RF power delivery is reduced when the target material is eroded

As the target becomes thinner, the physical distance from the surface of the magnet to the sputtering surface of the target decreases resulting in less efficient RF power transfer

In addition, the eroded tracks on the target surface further reduce the efficiency of RF power delivery, with which the eroded tracks can further confine electrons and thus reduce the plasma density at the substrate level

With increased magnetic confinement, electrons supplied by the RF current cannot propagate into the plasma as efficiently as they follow the enhanced (as a function of erosion depth) magnetic field lines

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