RF Test Gage R&R Improvement
Advanced cell phone architectures require high performance multi-throw RF switches. Reliably measuring the very low RF power levels of the third harmonic signal of these switches is a significant challenge. This paper discusses the use of Gage studies to identify and measure the sources of variation in RF probe measurements. Tester Gage study results are presented. Evaluations of factors including test instrument repeatability, probe card wear, probe tip planarity, probe pressure, and probe placement within the bond pad are presented. The data indicated the repeatability of the test instrumentation was very good. However, the reproducibility needed improvement. The most significant factor in achieving reproducible RF measurements is sufficient probe contact. A method to provide probe operators feedback of sufficient probe contact was developed and implemented. As a result, the Gage study passed. Further, the percentage of die requiring re-test was reduced significantly. INTRODUCTION State of the art multi-throw RF switches need to meet third harmonic performance specifications in the range of -30 to -40 dBm power at RF frequencies in the range of 824 to 915 MHz. -30 and -40 dBm correspond to 1uW and 100nW of power respectively. To provide known good switch die for Skyworks Front End Modules (FEM), the Skyworks pHEMT wafer fab performs RF probe testing on all switch die. Reliably making these low power measurements at high frequencies in a probe test environment requires advanced test instruments and rigid production discipline. The Skyworks Quality System requires Gage studies be performed on all measurement equipment. Further, Skyworks customers can and do request measurement system Gage study results.
Web-Based Business Intelligence for Semiconductor Manufacturing
Business Intelligence (BI) is a relatively new concept that has received a tremendous amount of coverage in recent manufacturing publications. The use of an integrated knowledge base in establishing best business practices is not new, but the demands of very high volume wireless semiconductor manufacturing with high product and process yields, combined with thin profit margins, has intensified effort in this area. This paper includes the architecture of the business intelligence solutions used at Skyworks and details how this integrated system is being used to improve our competitiveness in a global marketplace.
Ionization by drift and ambipolar electric fields in electronegative capacitive radio frequency plasmas.
Unlike α- and γ-mode operation, electrons accelerated by strong drift and ambipolar electric fields in the plasma bulk and at the sheath edges are found to dominate the ionization in strongly electronegative discharges. These fields are caused by a low bulk conductivity and local maxima of the electron density at the sheath edges, respectively. This drift-ambipolar mode is investigated by kinetic particle simulations, experimental phase-resolved optical emission spectroscopy, and an analytical model in CF(4). Mode transitions induced by voltage and pressure variations are studied.