No abstract

The development of a large-area plasma source with high density plasmas is desired for a variety of plasma processes from microelectronics fabrication to flat panel display device fabrication. In this study, a novel internal-type linear inductive antenna referred to as ''double comb-type antenna'' was used for a large-area plasma source with the substrate area of 880 mm 9 660 mm and the effect of plasma confinement by applying multi-polar magnetic field was investigated. High density plasmas on the order of 3.2 9 10 11 cm -3 which is 50% higher than that obtained for the source without the magnetic field could be obtained at the pressure of 15 mTorr Ar and at the inductive power of 5,000 W with good plasma stability. The plasma uniformity\3% could be also obtained within the substrate area. When SiO 2 film was etched using the double comb-type antenna, the average etch rate of about 2,100 Å /min could be obtained with the etch uniformity of 5.4% on the substrate area using 15 mTorr SF 6 , 5,000 W of rf power, and -34 V of dc-bias voltage. The higher plasma density with an excellent uniformity and a lower rf antenna voltage obtained by the application of the magnetic field are related to the electron confinement in a direction normal to the antenna line.

The variation in plasma uniformity over an extremely large size inductively coupled plasma ͑ICP͒ source of 2750ϫ 2350 mm 2 was examined. An internal linear-type antenna called "double comb-type antenna" was used as the ICP source. A plasma density of ϳ1.4ϫ 10 11 / cm 3 could be obtained at 5 mTorr Ar by applying 10 kW rf power to the source at a frequency of 13.56 MHz. An increase in rf power from 1 to 10 kW improved the plasma uniformity over a substrate area of 2300ϫ 2000 mm 2 from 18.1% to 11.4%. The improvement in uniformity of the internal ICP source was attributed to the increase in plasma density near the wall.

Effective plasma confinement by applying multipolar magnetic fields in an internal linear inductively coupled plasma system Magnetic fields and uniformity of radio frequency power deposition in low-frequency inductively coupled plasmas with crossed internal oscillating currents This study examined the effect of the antenna capacitance of an inductively coupled plasma ͑ICP͒ source, which was varied using an internal linear antenna, on the electrical and plasma characteristics of the ICP source. The inductive coupling at a given rf current increased with decreasing antenna capacitance. This was caused by a decrease in the inner copper diameter of the antenna made from coaxial copper/quartz tubing, which resulted in a higher plasma density and lower plasma potential. By decreasing the diameter of the copper tube from 25 to 10 mm, the plasma density of a plasma source size of 2750ϫ 2350 mm 2 was increased from approximately 8 ϫ 10 10 / cm 3 to 1.5ϫ 10 11 / cm 3 at 15 mTorr Ar and 9 kW of rf power.