Techniques For Extracting Dielectric Parameters In Silicon-Based Process

With the advent of the post-Moore era,the three-dimensional(3D)integration technology combining CMOS(complementary metal oxide semiconductor),MEMS(micro-electromechanical systems)and TSV(through-silicon via)technology has become an important drivering force to promote the sustainable evolution of the semiconductor industry.As one of the key parameters in RF and microwave design,dielectric constant actually is not invariable.Its performance at high frequencies is usually different from that at low frequencies,while semiconductor or printed circuit board manufacturers only offer dielectric data at low and discrete frequencies.Therefore,accurate extraction of permittivity at millimeter-wave and terahertz frequency region is of great significance,which ensures the predictability of performances of components and circuits processed.Based on the analysis of existing methods and the current research needs,this thesis researches on millimeter-wave dielectric characterization by using transmission/reflection method and resonance method around 140 GHz atmospheric window.Firstly,a method based on GCPW(grounded coplanar waveguide)is proposed for a specific 3D integration process,which can extract the permittivity of the substrate at broadband frequencies.TRL(thru-reflect-line)technology is utilized to accurately obtain the scattering parameters of the device under test(DUT).Combined with the characteristic analysis and numerical calculation of GCPW,the simulated results are consistent with the preset value,and the error of relative dielectric constant is less than 1%.Finally,the permittivity of silicon from110 GHz to 150 GHz is obtained after processing and measurement.Secondly,a method based on SIW(substrate integrated waveguide)transmission line is designed to realize the broadband extraction of the permittivity.The propagation constants obtained by solving the eigenvalues of matrix parameters in MATLAB are consistent with the de-embedded results based on TRL technique.The simulated results are in good agreement with the preset value and the maximum error of relative dielectric constant is 0.8%.For SIW has a closed structure,this design greatly reduces the influence of the external environment on the measurement and extraction.After processing and testing,the actual extracted permittivity is stable in the working frequency band,which further verifies the feasibility of the method.Thirdly,the single-port resonator processed by 0.18 μm CMOS is simulated and analyzed for permittivity extraction,combined with the traditional perturbation theory and Foster’s equivalent circuit model.The processing and testing is completed.In this design,the permittivity of dielectric materials can be extracted only by scattering parameters of one port without additional de-embedding structure.This design has compact structure and is convenient for measurement.The extracted results around 140 GHz are reliable and the method still has the potential for higher frequency application.In this thesis,millimeter-wave dielectric extraction is conducted around 140 GHz,and three different extracting schemes are designed.The measurements are simple and the extracted results are reliable.These are all effective methods to accurately extract permittivity at millimeter-wave or even terahertz frequencies,which serve as a solid foundation for subsequent design based on related processes.