Freescale Semiconductor

About: Freescale Semiconductor is a based out in . It is known for research contribution in the topics: Layer (electronics) & Signal. The organization has 7673 authors who have published 10781 publications receiving 149123 citations. The organization is also known as: Freescale Semiconductor, Inc..

Transistor sidewall spacer stress modulation

Abstract: A semiconductor fabrication process and the resulting integrated circuit include forming a gate electrode ( 116 ) over a gate dielectric ( 104 ) over a semiconductor substrate ( 102 ). A spacer film ( 124 ) exhibiting a tensile stress characteristic is deposited over the gate electrode ( 116 ). The stress characteristics of at least a portion of the spacer film is then modulated ( 132, 192 ) and the spacer film ( 124 ) is etched to form sidewall spacers ( 160, 162 ) on the gate electrode sidewalls. The spacer film ( 124 ) is an LPCVD silicon nitride in one embodiment. Modulating ( 132 ) the spacer film ( 124 ) includes implanting Xenon or Germanium into the spacers ( 160 ) at an implant energy sufficient to break at least some of the silicon nitride bonds. The modulation implant ( 132 ) may be performed selectively or non-selectively either before or after etching the spacer film ( 124 ).

Peak-to-average power ratio reduction in OFDM with blind selected pilot tone modulation

Abstract: Orthogonal frequency division multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels. However, the price paid for the high spectral efficiency is low power efficiency. OFDM signals suffer from high peak-to-average power ratios (PARs) which lead to power inefficiency in the RF portion of the transmitter. Selected mapping (SLM) is a promising technique to reduce the PAR of an OFDM signal and is distortionless. In this paper, we propose a novel technique which links the index of the phase rotation sequence in SLM to the location of the pilot tones that are used to estimate the channel. Each pilot tone location - phase sequence selection can lead to a different PAR value for the time-domain OFDM signal, and the signal with the lowest PAR value is transmitted. Our proposed method is "blind" in the sense that the optimum pilot tone location - phase sequence index is not transmitted as side information. We describe a novel technique to blindly detect the optimum index at the receiver. PAR reduction performance as well as BER performance of the proposed method in frequency selective fading channels are investigated

Pipelined memory having synchronous and asynchronous operating modes

Abstract: A pipelined memory (20) has a synchronous operating mode and an asynchronous operating mode. The memory (20) includes output registers (34) and output enable registers (48) which are used to electrically switch between the asynchronous operating mode and the synchronous operating mode. In addition, in the synchronous operating mode, the depth of pipelining can be changed between a three stage pipeline and a two stage pipeline. By changing the depth of pipelining, the memory (20) can operate using a greater range of clock frequencies. In addition, the operating frequency can be changed to facilitate testing and debugging of the memory (20).

Complementary metal-oxide-semiconductor field effect transistor structure having ion implant in only one of the complementary devices

Abstract: A complementary metal-oxide-semiconductor field effect transistor structure includes ion implants in only one of the two complementary devices. The transistor structure generally includes a compound semiconductor substrate and an epitaxial layer structure that includes one or more donor layers that establish a conductivity type for the epitaxial layer structure. The ion implants function to “invert” or “reverse” the conductivity type of the epitaxial layer structure in one of the complementary devices. In the example embodiment, p-type acceptor implants are utilized in the p-channel device, while the n-channel device remains implant-free.

Method and apparatus for asynchronous timing recovery using interpolation filter

Abstract: In an asynchronous communication system such as a V.32 modern (80), an input signal is sampled at a near-end clock rate. Each sample is then interpolated in an interpolation filter (92) to provide corresponding interpolated values. The interpolation filter (92) uses a selected one of a predetermined number of sets of windowed sinc function coefficients, each set having a successively greater phase offset. A time drift between near-end and far-end clocks is measured by tracking the coefficient shift in a passband phase-splitting, fractionally-spaced equalizer (95). When the time drift exceeds a threshold, a subsequent set of windowed sinc function coefficients is selected. When the time drift exceeds the threshold after the last set of coefficients is used, the first set is again selected and an interpolated value is either dropped or repeated in forming the far-end data samples.