TDDB evaluations and modeling of very high-voltage (10kV) capacitors

Abstract

Time-Dependent Dielectric Breakdown (TDDB) data for very thick (8um) silica-based dielectrics is reported at relatively low fields (< 5MV/cm) but at extremely high voltages (up to 4000V). TDDB data was taken across a wide range of dielectric thicknesses ranging from 38Å to 8μm (80,000Å). Consistent with the TDDB results generally reported for thin films, a thickness-independent effective dipole moment of ~13eÅ was concluded from the testing data. TDDB data is also presented for stacked dielectrics structures (Nitride/Silica) which tend to show a strong polarity dependence, depending on whether electron injection is into the nitride or oxide layer. While the time to failure is polarity dependent, the effective dipole moment is independent of polarity. [

Increases in Lorentz Factor with Dielectric Thickness

“…Thus, the extrinsic hypothesis will be rejected and an effort is undertaken to find a more fundamental physics-based model for describing why thicker dielectrics have lower breakdown strength and lower TDDB performance. This has great relevance for low-k interconnect dielectrics [20] and high-voltage capacitors [21] where the dielectrics can be relatively thick.…”

A face-to-face chip stacking 7kV RMS digital isolator for automotive and industrial motor drive applications

“…the breakdown time is not based on Weibull plot). This implies that >20-years lifetime with a working voltage of 1.5kV can be estimated based on E-model [3,4].…”

“…Since the insulation voltage of conventional isolators is determined by the thickness of the inter-layer dielectric between two coils of the transformer, a special CMOS process with 10~20μm-thick SiO 2 or polyimide deposition is required in order to achieve 2.5kV isolation voltage. This time-zero dielectric breakdown (TZDB) voltage roughly corresponds to the working voltage of 500V for 20 years [3,4], and it is the requirements of the motor drive systems for most of the electrical or hybrid vehicles. The special process, however, not only increases the wafer costs, but also causes large wafer warpage due to the mismatch in thermal expansion coefficients between the dielectric layer and Si-substrate.…”

Constant-current time dependent dielectric breakdown in thick amorphous SiO2 capacitors

“…Metal-insulator-metal (MIM) capacitors embedded in the back-end inter-level dielectric layers have been recently proposed for analog and RF applications [1]- [3]. Silicon dioxide (SiO 2 ) is the main insulator in the electronics industry because of its near-ideal properties; however, ultimate device degradation and failure is still limited by charge buildup in preexisting defect sites of the oxide layer.…”