Negative ion control for dielectric etch

• Main Authors: Bailey, III, Andrew D, Marakhtanov, Alexei, Hudson, Eric, Dhindsa, Rajinder, Abatchev, Mirzafer K
• Format: Patent
• Language: English
• Published: 15.01.2019
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OFNEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMICBEAMS; SEMICONDUCTOR DEVICES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

Apparatus, methods, and computer programs for semiconductor processing in a capacitively-coupled plasma chamber are provided. A chamber includes a bottom radio frequency (RF) signal generator, a top RF signal generator, and an RF phase controller. The bottom RF signal generator is coupled to the bottom electrode in the chamber, and the top RF signal generator is coupled to the top electrode. Further, the bottom RF signal is set at a first phase, and the top RF signal is set at a second phase. The RF phase controller is operable to receive the bottom RF signal and operable to set the value of the second phase. Additionally, the RF phase controller is operable to track the first phase and the second phase to maintain a time difference between the maximum of the top RF signal and the minimum of the bottom RF signal at approximately a predetermined constant value, resulting in an increase of the negative ion flux to the surface of the wafer.