Electrical Characteristics of Novel Non-porous Low-k Dielectric Fluorocarbon on Cu Interconnects for 22 nm Generation and Beyond

Abstract

In this study, the destruction of the contrast agent Sonazoid (GE Healthcare, Oslo, Norway) was measured in vitro as a function of centre frequency (2-3 MHz), acoustic amplitude (0.66-1.6 MPa), pulse length (2-16 cycles) and PRF (0.5-8.0 kHz). Up to 82% of microbubbles were destroyed after exposure to a single 1.6 MPa acoustic pulse (16 cycles, 2.5 MHz and PRF of 1.0 kHz), while at a low amplitude of 0.66 MPa, fractional destruction increased gradually from 0 to 40% after exposure to 9 (identical) pulses. Fractional destruction increased from approximately 8 to 66% as pulse length was changed from 2 to 16 cycles following exposure to a single 2.5 MHz, 1.3 MPa pulse. As the PRF was increased from 0.5 to 8.0 kHz, shorter exposure time intervals (from 4.8 to 1.2 ms) were needed to achieve the same fractional destruction of 80%. Conversely, as the transmit frequency was increased from 2 to 3 MHz the fractional destruction decreased (by more than half within the first 3 pulses). The influence of changes in acoustic pressure and duty cycle on the destruction of Sonazoid microbubbles was highly statistically significant (p 0.01) with a threshold around 0.67 MPa for a duty cycle of 0.0064. In conclusion, the fractional destruction increases with the duty cycle and the acoustic pressure amplitude and decreases with ultrasonic transmit frequency. Better understanding of the influence of the ultrasound transmit parameters on the destruction of contrast microbubbles should help improve existing contrastassisted imaging modalities and may help develop new techniques for better use of contrast agents.

Integration Process Development for Improved Compatibility with Organic Non-Porous Ultralow-k Dielectric Fluorocarbon on Advanced Cu Interconnects

“…[2][3][4][5][6] An alternative organic non-porous fluorocarbon is considered as an indispensable ultralow-k (ULK) dielectric to minimize complexity of LSI fabrication. [7][8][9][10][11] This new fluorocarbon material was prepared by microwave-excited plasma-enhanced chemical vapor deposition (MWPE-CVD) using an advanced microwave at 2.45 GHz. 7,8) The microwave plasma indicates a low electron temperature (approximately 1-2 eV) with high plasma density and it sufficiently avoids ion bombardment to the substrate.…”

“…This novel non-porous ULK dielectric fluorocarbon formed by MWPE-CVD has been successfully integrated into Cu damascene interconnects in our previous study. [9][10][11] In this study, we explored the integration process-induced damage in delamination and the variances of both structure and electrical characteristics of fluorocarbon induced by wet chemical cleaning and dry etching during Cu/fluorocarbon damascene interconnects fabrication. The integration of the non-porous ULK fluorocarbon without dielectric fluorocarbon degradation into advanced Cu interconnects was also improved.…”

Robust Ultralow-k Dielectric (Fluorocarbon) Deposition by Microwave Plasma-Enhanced Chemical Vapor Deposition

“…Remarkably, this fluorocarbon film was successfully integrated into single Cu damascene interconnects. 9,10) When fluorocarbons are, however, applied to a practical multilevelwiring process, improvement of to the thermal stability of fluorocarbons is still required to improve their adhesion to and comparability with many other films used for interlayer dielectrics, e.g., silicon oxide (SiO x ).…”

Advanced Direct-Polishing Process Development of Non-Porous Ultralow-kDielectric Fluorocarbon with Plasma Treatment on Cu Interconnects

“…[1][2][3][4][5][6] An organic non-porous ULK dielectric, fluorocarbon (k = 2.2), has been integrated into Cu damascene interconnects as an alternative dielectric to avoid integration-process-induced damage in LSI fabrication. [7][8][9][10][11][12] The ULK dielectric fluorocarbon film was deposited using an advanced microwave (2.45 GHz) exited dual-showerplate structure plasma reactor. The microwave plasma produced by the radial line slot antenna indicates high density and low electron temperature (around 1-2 eV), which prevents ion bombardment damage to the substrates.…”

“…7,8 Therefore, the ULK dielectric fluorocarbon deposited by the microwave excited plasma-enhanced chemical vapor deposition (MWPE-CVD) shows good material properties with a low k-value and robust behavior in terms of dielectric constant variation during the Cu damascene integration fabrication process, compared with porous SiCO:H films and fluorocarbon deposited by conventional PE-CVD using a parallel plate plasma reactor. [7][8][9][10][11][12][13][14] In this developed damascene integration process, a nitrogen plasma treatment (NPT) was applied as a post-dry-etching process to minimize damage to fluorocarbon in the following damascene fabrication processes, such as the post-etching cleaning. 11,12 Even though a dielectric protective layer has been used on the surface of low-k dielectrics in the conventional polishing process to avoid damage induced by CMP, the k-value of the dielectric protective layer is much higher than that of low-k dielectric, which results in the high value of k eff .…”