Planar microwave discharges with active control of plasma uniformity

Abstract

Planar microwave discharges using a multi-slotted planar antenna are investigated. The enhancement of the microwave fields near the plasma resonance is observed in accordance with the theory of the resonant absorption. By operating the antenna with the azimuthally rotating fields, highly uniform overdense plasmas can be produced without being affected by eigenmode structures of surface waves. As a result, the radial distribution of the ion saturation current can be controlled by tailoring the power radiation profile from the antenna. It is also demonstrated that the active control of the plasma uniformity is possible by simply changing the vertical position of the antenna.

Impact of static magnetic fields on the radial line slot antenna plasma source

“…[8][9][10][11][12] show that manipulating the position of the plasma generation in the bulk radially is most important for plasma profile controllability. Axial magnetic fields of varying magnitude combined with slots placed at larger radii make this effect possible.…”

“…Above a critical density ($3 Â 10 17 m À3 ), surface wave modes are produced with the plasma density generally peaking at the location of peak electric field. A series of papers by Sugai et al [4][5][6] describe the properties of the generation region while a series of papers by Yasaka et al 7,8 illustrate the impact of the antenna structure on the form of the coupled microwave field and consequent plasma. The radial line slot antenna plasma source is characterized as having low electron temperature and high plasma density near the wafer, which translates to low damage and high process (e.g., etch) rates.…”

High-power microwave discharge for producing large-area surface-wave plasmas

“…Therefore, SWP have been exhaustively investigated both theoretically and experimentally [1][2][3][4][5][6]. For example, M. Nagatsu et al [2] have yielded large-area surface-wave plasmas with an internally mounted planar cylindrical launcher, Y. Yasaka et al [7][8][9] have produced large-diameter uniformity plasma using multislotted planar antenna, and C. Tian et al [10] have studied characteristics of large-diameter plasma using a radial-line slot antenna. But most of the structure of chamber reported in the literature is circular cylinder; a rectangular cavity [11][12][13] is adopted in this article.…”

Exciting Vorticity Through Higher Order Bessel Beams With a Radial-Line Slot-Array Antenna

“…Due to their peculiar phase rotation, these beams have recently received a great interest at radiofrequencies and microwaves. Indeed, OAM can be potentially capable, among other applications, of an increased capacity of communication channels [3], enhanced remote sensing [4], and plasma control [5], [6].…”