Etching Characteristics by M= 0 Helicon Wave Plasma

Tsukada, Tsutomu; Nogami, Hiroshi; Nakagawa, Yukito; Wani, Etsuo

doi:10.1143/jjap.33.4433

Cited by 26 publications

(14 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Cl 2 flow rate was 50 sccm, and the bias power was kept at 55 W. The TiN etch rate decreased as the pressure increased, except for the low pressure regime (pϽ4 mTorr͒. This result is similar to the aluminum etch behavior in a Cl 2 /BCl 3 helicon-wave plasma 11,12 and the TiN etch behavior in an SF 6 /Ar helicon plasma. 4 In contrast to the TiN etch response, the etch rate of SiO 2 increased monotonically as the pressure increased from 2.5 to 10 mTorr.…”

Section: Effect Of Bias Powersupporting

confidence: 55%

Characterization of titanium nitride etch rate and selectivity to silicon dioxide in a Cl2 helicon-wave plasma

Chiu

Lin

et al. 2001

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

Influence on selective SiO 2 /Si etching of carbon atoms produced by CH 4 addition to a C 4 F 8 permanent magnet electron cyclotron resonance etching plasmaThe effects of Cl 2 and N 2 flow rate, substrate bias power, and reaction pressure on both the titanium nitride and SiO 2 etch rate plus the etch selectivity of TiN/SiO 2 in a high-density helicon-wave plasma were studied. It was found that the bias power has the greatest effect on etch rate and selectivity, followed by the reaction pressure. As the bias power increased, both the TiN and SiO 2 etch rate increased significantly. This result is consistent with the fact that the dominant etch mechanism for both SiO 2 and TiN is an ion-assisted energy driven etch mechanism rather than pure chemical etching. As the SiO 2 etch rate is drastically reduced from 403 Å/min to near zero when the bias power is decreased from 70 to 20 W, the etch selectivity of TiN to SiO 2 significantly rises from 55 to over 500. The effect of pressure was found to be more complex, having a different effect on the etch rate of TiN versus SiO 2 . By increasing the pressure from 2.5 to 4 mTorr, the TiN etching rate rose to a maximum at 4 mTorr and then monotonically decreased up to a pressure of 10 mTorr. This result is similar to aluminum etching in a Cl 2 /BCl 3 helicon-wave plasma. In contrast to the TiN etch behavior, the etch rate of SiO 2 increased monotonically over the full pressure range investigated. In addition to the effect on etch rate, the etch selectivity of TiN to SiO 2 noticeably increased with increasing pressure. Optical-emission spectroscopy was used to investigate the cause. It was determined that the effect of pressure on etch rate and selectivity could be explained by the change of atomic Cl radical density, ion flux, and ion energy. It was also observed that both the etch rate of TiN and SiO 2 slightly increased as Cl 2 flow rate increased from 10 to 90 sccm, reaching a maximum at about 70 sccm. The selectivity of TiN to SiO 2 remained around 8-11 in this Cl 2 flow rate range. The addition of N 2 seems to have only a small effect on etch rate.

show abstract

Section: Effect Of Bias Powersupporting

confidence: 55%

Characterization of titanium nitride etch rate and selectivity to silicon dioxide in a Cl2 helicon-wave plasma

Chiu

Lin

et al. 2001

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

View full text Add to dashboard Cite

show abstract

“…During the past decade, a large number of papers have appeared regarding the use of helicon sources in actual plasma processing applications [89]- [123], and the number is increasing rapidly. Review of this work is beyond the scope of this paper; however, some generalizations can be made.…”

Section: Industrial Applicationsmentioning

confidence: 99%

Helicons-the past decade

Chen¹,

Boswell

1997

IEEE Trans. Plasma Sci.

305

178

View full text Add to dashboard Cite

First observed in gaseous plasmas in the early 1960's, helicon discharges lay like a sleeping giant until they emerged in the 1980's, when their usefulness as efficient plasma sources for processing microelectronic circuits for the burgeoning semiconductor industry became recognized. Research on helicons spread to many countries; new, challenging, unexpected problems arose, and these have spawned solutions and novel insights into the physical mechanisms in magnetized radio-frequency discharges. Among the most baffling puzzles were the reason for the high ionization efficiency of helicon discharges and the dominance of the right-hand polarized mode over the left-hand one. The most recent results indicate that a nonobvious resolution of these problems is at hand.

show abstract

“…Plasmas can be produced very efficiently by using helicon waves, or whistler waves propagating in a bounded plasma region, whose frequency is x ci ( x ( x ce , where x ci and x ce are the ion-and electron-cyclotron frequencies, respectively. [1][2][3][4] Because it is possible to easily obtain high-density ($10 13 cm À3 ) plasmas with high ionization rate (several tens of percent) under a wide range of magnetic field strength in helicon-wave discharge, helicon plasma sources are suitable for various plasma applications, such as basic science experiments, [5][6][7] developing magnetoplasma rocket engines, 8,9 plasma processings, 10,11 and fusion related experiments. 12 A low-aspect ratio plasma source with uniform density profile is especially useful for such applications like plasma processings and plasma thrusters.…”

Section: Introductionmentioning

confidence: 99%

Characteristics of low-aspect ratio, large-diameter, high-density helicon plasmas with variable axial boundary conditions

et al. 2012

View full text Add to dashboard Cite

A low-aspect ratio, high-density helicon plasma source with a large-diameter of $74 cm that utilizes an end-launch flat-spiral antenna has been characterized under three different axial boundary conditions. Whereas one end of the device is a quartz-glass window through which an excitation rf wave is injected, the other end is a movable plasma terminating plate of three different kinds: (1) metal with small holes, (2) solid metal, and (3) solid insulator. Using this movable plate, the device aspect ratio A (device axial length/device diameter) can be reduced to $0.075 corresponding to the device axial length of 5.5 cm. The plasma production efficiency (PPE, defined as the ratio of the total number of electrons in the plasma to the input rf power) and helicon wave structures are examined for plasmas with various aspect ratios and boundary conditions to characterize our helicon device. Even for the lowest aspect ratio case (A $0.075), a plasma with the electron density of 7.5 Â 10 11 cm À3 can be produced. The PPE of our device is higher than that of other helicon devices that utilize winding-type antennas. Discrete axial wave modes, which can be explained by a simple model, have been identified for helicon waves excited in our low-aspect ratio helicon plasmas. A comparison between the experimental results and helicon wave theory suggests that second order radial modes must have been excited when the electron density is sufficiently high. V

show abstract

Etching Characteristics by M= 0 Helicon Wave Plasma

Cited by 26 publications

References 9 publications

Characterization of titanium nitride etch rate and selectivity to silicon dioxide in a Cl2 helicon-wave plasma

Characterization of titanium nitride etch rate and selectivity to silicon dioxide in a Cl2 helicon-wave plasma

Helicons-the past decade

Characteristics of low-aspect ratio, large-diameter, high-density helicon plasmas with variable axial boundary conditions

Contact Info

Product

Resources

About