In this paper we introduce, a state-of-the-art SiGe BiCMOS power amplifier technology that features two NPNs with 40 GHz / 6.0 V & 27 GHz / 8.5 V (fT -BVceo) respectively, a novel low inductance metal ground through-silicon-via (TSV), integrated on a low-cost 0.35 ,um lithography node with 3.3 V / 5.0 V dualgate CMOS technology and high-quality passives on a 50 Q.cm substrate. INTRODUCTIONToday for RF radio applications, the system is partitioned to minimize the overall cost, size, and power. Competing approaches with system-on-a-chip and system-in-a-package effectively address this system partitioning. Based on these approaches, the RF transceiver and front-end-modules (FEM) integration is still a battleground for multiple technologies. Of particular interest is the power amplifier (PA) integration trend. Compared to the transceiver, the FEM elements, such as, PA and switch need to support very harsh environment for power and linearity. Stringent system specifications requirements related to output power, linearity, efficiency etc. force system designers to partition the FEM as a separate packaged module. In effect, this allows the use of best possible technology for the lowest cost module [1]. This situation is expected to get worse in future wireless communication systems where the FEMs need to integrate multi-mode and multi-band PAs with better form-factor and cost. Silicon technology remains as an excellent candidate for providing such an integration path. SiGe BiCMOS has made substantial in-road into PA market segment with the explosion of WLAN applications at 2.4 GHz. A 0.5um SiGe BiCMOS technology [2] optimized for power amplifier design has provided a stepping stone for this application. SiGe BiCMOS integration allows several benefits compared to GaAs HBTs, such as, integrated biasing and regulator to manage battery voltage, temperature compensated

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Physical and device characteristics of sub-30 Å oxynitride gate dielectrics with different nitrogen concentrations are compared. These dielectrics are formed in a standard atmospheric furnace that is in series with a gas precombustion chamber. All gases flow through the precombustion chamber prior to reacting with the wafers. The layers are formed by oxidation of silicon in a N 2 O ͑nitrous oxide͒ ambient. By changing the precombustion chamber temperature from 850°to 950°C, the nitrogen content is changed by up to a factor of five as measured by electron spectroscopy for chemical analysis and time-of-flight secondary ion mass spectrometry. A change in oxidation growth rate across the temperature range is observed with a decrease in growth rate for higher precombustion temperatures. The nitrogen content also modifies the refractive index of the film such that for a 24 Å optical thickness, a physical thickness delta of 2 Å is observed, with the thickness at 950°C 2 Å less than at 850°C. Complementary metal oxide semiconductor devices on silicon-on-insulator substrates formed with hotter precombustion temperatures exhibit a two-time reduction in leakage current density.The speed requirements for high-performance 0.25 m complementary metal oxide semiconductor ͑CMOS͒ devices has driven gate oxide thicknesses to less than 30 Å, with inversion thicknesses trending toward sub-30 Å and physical thicknesses to less than 20 Å. 1 As the dielectric layers are scaled thinner, the leakage currents through these gates exponentially increase due to more direct tunneling of electrons through the potential barrier of the dielectric. 2 This can affect device properties by causing higher standby power consumption, reliability problems, and degradation of certain chip functions such as timing. 3 Boron penetration in p-type devices is also a problem for thin dielectric layers and will degrade the timedependent-dielectric-breakdown ͑TDDB͒ reliability. 4 As a result of these issues, many different solutions and methods have been reported using nitrided gate dielectrics, where nitrogen is incorporated into the SiO 2 ͑silicon dioxide͒ layer. Nitrided gate solutions have included postannealing in N 2 O and NO ͑nitric oxide gas͒, in situ growth using N 2 O and NO, nitrogen ion implant, and more exotic processes including nitrogen plasma treatments and chemical vapor deposition ͑CVD͒ layered stacks. 5-10 For nitrogen doses between 10 13 and 10 14 atom/cm 2 , an excellent barrier to boron penetration is formed and reliability is improved. This has been reported to be due to the bonding of nitrogen to the dangling bonds of defect centers at the interface of the dielectric and substrate. 11 For aggressively scaled technologies, where gate leakage current becomes a significant contributor to the total off-current of the device, further nitrogen incorporation is desirable such that the dielectric constant of the layer is increased. With the increase in nitrogen incorporation, however, a corresponding increase in fixed positive charge occurs, which...

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