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We report a low phase noise transformer-coupled CMOS VCO using a bias-level shifting technique. Two fully integrated voltage-controlled oscillators (VCOs) are presented as a proof of concept. A conventional LC VCO with a current source achieves a phase noise of -116.67 dBc/Hz at 1 MHz offset from the 5.6 GHz center frequency, taking 3.9 mA from a 1.5 V(More)
We selected a sputtered-Zn(O,S) film as a buffer material and fabricated a Cu(In,Ga)Se2 (CIGS) solar cell for use in monolithic tandem solar cells. A thermally stable buffer layer was required because it should withstand heat treatment during processing of top cell. Postannealing treatment was performed on a CIGS solar cell in vacuum at temperatures from(More)
—This paper presents the measurement and characterization of multilayered interconnect capacitances for a 0.35-m CMOS logic technology, which become a critical circuit limitation to high performance VLSI design. To measure multilayered capacitances of nonstacked, stacked, and orthogonally crossing interconnect lines, new test structures and measurement(More)
  • Woo-Jung Lee, Hye-Jung Yu, +6 authors Yong-Duck Chung
  • 2016
We fabricated Cu(In,Ga)Se2 (CIGS) solar cells with a chemical bath deposition (CBD)-ZnS buffer layer grown with varying ammonia concentrations in aqueous solution. The solar cell performance was degraded with increasing ammonia concentration, due to actively dissolved Zn atoms during CBD-ZnS precipitation. These formed interfacial defect states, such as(More)
We fabricated Cu(In,Ga)Se2 (CIGS) solar cells with chemical-bath deposited (CBD) ZnS buffer layers with different deposition times. The conversion efficiency and the fill factor of the CIGS solar cells reveal a strong dependence on the deposition time of CBD-ZnS films. In order to understand the detailed relationship between the heterojunction structure and(More)
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