Abstract: A method includes: receiving a ranging signal from the transmitter including a set of multiplexed sub-signals, each multiplexed sub-signal characterized by a frequency in a set of frequencies; calculating a sample-based time-of-arrival estimate based on the series of time-domain samples of the ranging signal; calculating a sample-based uncertainty of the sample-based time-of-arrival; for each sub-signal pair in a subset of multiplexed sub-signals of the set of multiplexed sub-signals, extracting a phase difference of the sub-signal pair; calculating a phase-based time-of-arrival estimate based on the phase difference of each sub-signal pair in the subset of multiplexed sub-signals; calculating a phase-based uncertainty of the phase-based time-of-arrival estimate; and calculating a hybrid time-of-arrival estimate as a weighted combination of the sample-based time-of-arrival estimate, the phase-based time-of-arrival estimate, based on the sample-based uncertainty and the phase-based uncertainty.

Abstract: A method for etching features into an etch layer disposed below a photoresist mask without an intermediate hardmask is provided. A plurality of etch cycles are provided. Each etch cycle comprises providing a deposition etch phase that etches features into the etch layer and deposits polymer on sidewalls of the features and over the photoresist and providing a cleaning phase that removes polymer deposited on the sidewalls.

Abstract: A method for providing features in an etch layer with a memory region and a peripheral region is provided. A memory patterned mask is formed over a first sacrificial layer. A first set of sacrificial layer features is etched into the first sacrificial layer and a second sacrificial layer. Features of the first set of sacrificial layer features are filled with filler material. The first sacrificial layer is removed. The spaces are shrunk with a shrink sidewall deposition. A second set of sacrificial layer features is etched into the second sacrificial layer. The filler material and shrink sidewall deposition are removed. A peripheral patterned mask is formed over the memory region and peripheral region. The second sacrificial layer is etched through the peripheral patterned mask. The peripheral patterned mask is removed. Features are etched into the etch layer from the second sacrificial layer.

Abstract: A feature in a layer is provided. A photoresist layer is formed over the layer. The photoresist layer is patterned to form photoresist features with photoresist sidewalls, where the photoresist features have a first critical dimension. A conformal layer is deposited over the sidewalls of the photoresist features to reduce the critical dimensions of the photoresist features. Features are etched into the layer, wherein the layer features have a second critical dimension, which is less than the first critical dimension.