Abstract: Improved control of via anchor profiles in metals at a contact layer can be achieved by slowing down an anchor etching process and by introducing a passivation operation. By first passivating a metallic surface, etchants can be prevented from dispersing along grain boundaries, thereby distorting the shape of the via anchor. An iterative scheme that involves multiple cycles of alternating passivation and etching operations can control the formation of optimal via anchor profiles. When a desirable anchor shape is achieved, the anchor maintains structural integrity of the vias, thereby improving reliability of the interconnect structure.

Abstract: In some implementations, fluorine is oxidized after dry etching an oxide layer above a source/drain contact and before cleaning. Accordingly, less hydrofluoric acid is formed during cleaning, which reduces unexpected wet etching of the source/drain contact. This allows for forming a recess in the source/drain contact with a depth to width ratio in a range from approximately 1.0 to approximately 1.4 and prevents damage to a layer of silicide below the source/drain that can be caused by excessive hydrofluoric acid. Additionally, or alternatively, the recess is formed using multiple wet etch processes, and any residual fluorine is oxidized between the wet etch processes. Accordingly, each wet etching process may be shorter and less corrosive, which allows for greater control over dimensions of the recess. Additionally, less hydrofluoric acid may be formed during cleaning processes between the wet etch processes, which reduces the etching of the source/drain contact between processes.

Abstract: In some implementations, fluorine is oxidized after dry etching an oxide layer above a source/drain contact and before cleaning. Accordingly, less hydrofluoric acid is formed during cleaning, which reduces unexpected wet etching of the source/drain contact. This allows for forming a recess in the source/drain contact with a depth to width ratio in a range from approximately 1.0 to approximately 1.4 and prevents damage to a layer of silicide below the source/drain that can be caused by excessive hydrofluoric acid. Additionally, or alternatively, the recess is formed using multiple wet etch processes, and any residual fluorine is oxidized between the wet etch processes. Accordingly, each wet etching process may be shorter and less corrosive, which allows for greater control over dimensions of the recess. Additionally, less hydrofluoric acid may be formed during cleaning processes between the wet etch processes, which reduces the etching of the source/drain contact between processes.

Abstract: The present disclosure provides a semiconductor structure, including a substrate, a gate structure over the substrate, including a work function layer over the substrate, a dielectric layer at least partially surrounding the gate structure, and a capping layer over the gate structure, wherein a bottom of the capping layer includes at least one protrusion protruding toward the substrate.

Abstract: Improved control of via anchor profiles in metals at a contact layer can be achieved by slowing down an anchor etching process and by introducing a passivation operation. By first passivating a metallic surface, etchants can be prevented from dispersing along grain boundaries, thereby distorting the shape of the via anchor. An iterative scheme that involves multiple cycles of alternating passivation and etching operations can control the formation of optimal via anchor profiles. When a desirable anchor shape is achieved, the anchor maintains structural integrity of the vias, thereby improving reliability of the interconnect structure.

Abstract: In some implementations, fluorine is oxidized after dry etching an oxide layer above a source/drain contact and before cleaning. Accordingly, less hydrofluoric acid is formed during cleaning, which reduces unexpected wet etching of the source/drain contact. This allows for forming a recess in the source/drain contact with a depth to width ratio in a range from approximately 1.0 to approximately 1.4 and prevents damage to a layer of silicide below the source/drain that can be caused by excessive hydrofluoric acid. Additionally, or alternatively, the recess is formed using multiple wet etch processes, and any residual fluorine is oxidized between the wet etch processes. Accordingly, each wet etching process may be shorter and less corrosive, which allows for greater control over dimensions of the recess. Additionally, less hydrofluoric acid may be formed during cleaning processes between the wet etch processes, which reduces the etching of the source/drain contact between processes.

Abstract: A method may include generating a frequency-agnostic signal using an adjustable oscillator, and applying the frequency-agnostic signal to a user. The method may also include determining a reflecting value based on the frequency-agnostic signal as reflected by the user. The method may additionally include identifying a peak in the reflecting value by at least repeatedly comparing the determined reflecting value to a previously stored highest reflecting value, and adjusting the adjustable oscillator based on the comparison. The method may also include, after identifying the peak, determining a frequency of the oscillator corresponding to the peak, and outputting the frequency of the oscillator.

Abstract: A method and device to track navigational satellite signals, are claimed. In this invention, a combination of down-sampling and frequency domain transformation are used to track the navigational satellite signals under dynamic environment. A Fast Fourier Transform (FFT) with long coherent integration has been employed to determine the varying frequency components with high resolution. By representing a number of correlation values with their average value, it is possible to represent a long sequence of input values by a smaller number of values and a relatively short length FFT can reveal the low frequency components that are present in the signal during tracking operation. A large reduction in the computational load may be achieved using this down-sampling method without compromising on the frequency resolution.

Abstract: The present invention provides systems and methods for faster acquisition and more stable tracking of spread spectrum signals with lower computational load requirements. Instead of the present day practice of using only the Prompt correlator, the systems and methods of the invention use the sum of the powers of all the correlators of a channel to determine the acquisition or tracking of the signal. These systems and methods improve the signal acquisition speed resulting in a reduced Time-To-First-Fix (TTFF). Further, these systems and methods improve the acquisition and tracking sensitivity of the receiver.

Abstract: The present invention provides systems and methods for downloading navigation data to a satellite receiver under weak signal conditions. In an embodiment, the receiver uses a tracking algorithm to estimate the Doppler frequency and rate of change of the Doppler frequency to compensate the phases of the I/Q samples from the received signal to reduce the effect of the Doppler frequency. In an embodiment, differential detection based data bit decoding is provided. In another embodiment, phase compensation based data bit decoding is provided, in which the phase of samples are rotated to compensate for phase error. In an embodiment, a multiple frame strategy is provided to increase signal-to-noise ratio (SNR) and improve sensitivity, in which similar placed samples in consecutive frames are coherently summed over the consecutive frames. In an embodiment, the samples are weighted to reduce the impact of noise in the multiple frame strategy.

Abstract: The present invention provides systems and methods for downloading navigation data to a satellite receiver under weak signal conditions. In an embodiment, the receiver uses a tracking algorithm to estimate the Doppler frequency and rate of change of the Doppler frequency to compensate the phases of the I/Q samples from the received signal to reduce the effect of the Doppler frequency. In an embodiment, differential detection based data bit decoding is provided. In another embodiment, phase compensation based data bit decoding is provided, in which the phase of samples are rotated to compensate for phase error. In an embodiment, a multiple frame strategy is provided to increase signal-to-noise ratio (SNR) and improve sensitivity, in which similar placed samples in consecutive frames are coherently summed over the consecutive frames. In an embodiment, the samples are weighted to reduce the impact of noise in the multiple frame strategy.

Abstract: The present invention provides systems and methods for downloading navigation data to a satellite receiver under weak signal conditions. In an embodiment, the receiver uses a tracking algorithm to estimate the Doppler frequency and rate of change of the Doppler frequency to compensate the phases of the I/Q samples from the received signal to reduce the effect of the Doppler frequency. In an embodiment, differential detection based data bit decoding is provided. In another embodiment, phase compensation based data bit decoding is provided, in which the phase of samples are rotated to compensate for phase error. In an embodiment, a multiple frame strategy is provided to increase signal-to-noise ratio (SNR) and improve sensitivity, in which similar placed samples in consecutive frames are coherently summed over the consecutive frames. In an embodiment, the samples are weighted to reduce the impact of noise in the multiple frame strategy.

Abstract: The present invention provides systems and methods for enabling a navigation signal receiver to perform both data assisted and non-data assisted integration to provide better integration during signal acquisition, reacquisition and tracking. In data assisted integration mode, a receiver uses known or predicted data bits to remove the modulated data bits of a received signal prior to integration. In non data assisted integration mode, when the data bits are not known or predictable, the receiver uses an optimal estimation or maximum likelihood algorithm to determine the polarities of the modulated data bits of the received signal. This may be done by determining which of various possible bit pattern yields the maximum integrated power. When the modulated data bits are not known or predictable over a limited range, the receiver carries out data assisted integration over the known or predictable data bits and additional non data assisted integration.

Abstract: The present invention provides systems and methods for navigational signal tracking in low power mode to conserve the power of handheld navigation receivers. In an embodiment, the receiver cycles between sleep and wakeup states. During the sleep state, most of the components of the receiver are powered off to conserve power, and during the wakeup state, the receiver tracks navigational signals. In an embodiment, the duty cycle of the sleep/wakeup states depends on the receiver dynamic state, e.g., whether the receiver is accelerating. In another embodiment, during the wakeup state, the receiver selects a tracking mode based on the signal strength. Under weak signal conditions, a tracking mode using a long integration to track the satellite signal is disclosed. In one embodiment, a tracking mode tracks the navigation signal by performing data aided integration using known or predicted data bits, such as the TLM and HOW words.

Abstract: Methods to achieve data bit synchronization from weak navigational satellite signals are based on a maximum likelihood criterion. The bit synchronization technique may be implemented by calculating a normalized dot product of two consecutive one-millisecond correlation values. Similar normalized dot products are calculated at intervals separated by one bit duration, and these dot products are summed and compared with pre-computed thresholds to declare bit edge detection. In another implementation, the normalized dot product of adjacent correlation values is replaced by a coherent integration powers of adjacent correlation values.

Abstract: Provided herein is multi-function platform comprising a plurality of devices and a large memory that is external to the devices and shared among the devices. In an embodiment, a Direct Memory Access (DMA) controller is provided for each device to efficiently transfer data between the device and the shared memory. More than one DMA may be provided for a device. For example, separate DMAs may be provided for different components of a device that perform different subfunctions enabling efficient transfer of data between the different components of the device and the shared memory. In another embodiment, each device comprises a local embedded memory and is provided with a DMA for transferring data between the local memory and the shared memory. Examples of devices that can be included in the platform include a GNSS receiver, a audio player, a video player, a wireless communication device, a routing device, or the like.

Abstract: Fast Fourier Transform (FFT) based Phase Lock Loops (PLLs) are provided for use in navigational signal receivers. In an embodiment, a navigation receiver correlates a received navigational signal with a locally generated signal into correlation samples, e.g., one-millisecond correlation samples. The navigation receiver includes a FFT based PLL that corrects phase shifts in the correlation samples due to the Doppler frequency by considering both the Doppler frequency and its rate of change, which are obtained from a FFT computation with interpolation. The phase corrected correlation samples are then integrated over a length of a navigation data bit, e.g., 20 milliseconds, to determine the sign of the data bit of the received signal. In another embodiment, a soft decision feedback technique involving integration extending over the present data bit and several prior data bits is used to determine the sign of a present data bit of the received signal.

Abstract: A method to determine the polarity of navigation data from weak satellite signals is disclosed. After bit edge is detected, a method in frequency domain is used to determine the present bit polarity with the help of several prior data bits which are already known, is disclosed. The impact of residual frequency can be mitigated by frequency transform. This method is especially useful in removing the data modulation in the weak signal for subsequent long coherent integrations.

Abstract: Systems and methods are provided that compensate for frequency drift due to temperature variation without the need for a temperature sensor. In one embodiment, a navigation receiver with an integrated communication device receives a base station reference signal, which is used to periodically calibrate a local oscillator frequency. In another embodiment, the calibrated local oscillator frequency drives a counter that is used to provide code phase estimation at the start of satellite signal acquisition. To provide temperature compensation in one embodiment, the calibrated local frequency is used to drive one or more counters at different calibration rates (i.e., different time intervals between calibrations). Count values from these counters are used to determine compensation for frequency drift due to temperature variation based on predicted frequency drift variation patterns between calibrations.

Abstract: The present invention provides GPS receivers capable of tracking very weak GPS signals particularly in an indoor environment without assistance from an external server or a network. In a preferred embodiment, a GPS receiver initially acquires and locks onto GPS satellite signals to compute receiver position outdoors. The GPS receiver then tracks at least one satellite signal indoors to maintain acquisition parameters for quick acquisition of GPS signals. To save power, the receiver automatically goes to the sleep state and periodically wakes up, i.e., powers up, to maintain the at least one satellite signal tracking. During the wakeup state, the receiver collects ephemeris data from the at least one satellite signal when the ephemeris data needs to be updated for quick acquisition of GPS signals.