VHF/UHF plasma process for use in forming integrated circuit structures on semiconductor wafers

摘要

A method of fabricating integrated circuit structures on semiconductor wafers using a plasma-assisted process is disclosed wherein the plasma is generated by a VHF/UHF power source at a frequency ranging from about 50 to about 800 MHz. Low pressure plasma-assisted etching or deposition processes, i.e., processes may be carried out within a pressure range not exceeding about 500 milliTorr; with a ratio of anode to cathode area of from about 2:1 to about 20:1, and an electrode spacing of from about 5 cm. to about 30 cm. High pressure plasma-assisted etching or deposition processes, i.e., processes may be carried out with a pressure ranging from over 500 milliTorr up to 50 Torr or higher; with an anode to cathode electrode spacing of less than about 5 cm. By carrying out plasma-assisted processes using plasma operated within a range of from about 50 to about 800 MHz, the electrode sheath voltages are maintained sufficiently low, so as to avoid damage to structures on the wafer, yet sufficiently high to preferably permit initiation of the processes without the need for supplemental power sources. Operating in this frequency range may also result in reduction or elimination of microloading effects.