Abstract: A method for multi-state pulsing to achieve a balance between bow control and mask selectivity is described. The method includes generating a primary radio frequency (RF) signal. The primary RF signal pulses among three states including a first state, a second state, and a third state. The method further includes generating a secondary RF signal. The secondary RF signal pulses among the three states. During the first state, the primary RF signal has a power level that is greater than a power level of the secondary RF signal. Also, during the second state, the secondary RF signal has a power level that is greater than a power level of the primary RF signal. During the third state, power levels of the primary and secondary RF signals are approximately equal.

Abstract: A method for forming features in dielectric layers and opening barrier layers for a plurality of wafers and cleaning an etch chamber after processing and removing each wafer of the plurality of wafers is provided. A wafer of the plurality of wafers is placed into the etch chamber wherein the wafer has a barrier layer over the wafer and a dielectric layer over the barrier layer. The dielectric layer is etched. The barrier layer is opened. The wafer is removed from the etch chamber. A waferless automatic cleaning of the etch chamber without the wafer is provided. The waferless automatic cleaning comprises providing a waferless automatic cleaning gas comprising oxygen and nitrogen to the etch chamber and forming a waferless automatic cleaning plasma from the waferless automatic cleaning gas to clean the etch chamber.

Abstract: A method for controlling a photoresist etch step in a plasma processing chamber is disclosed. The photoresist etch step being configured to etch back a photoresist layer deposited on a substrate surface to a thinner photoresist layer having predefined photoresist thickness. The method includes etching the photoresist layer using a plasma etch process and detecting interference patterns coming from the photoresist layer. The method further includes terminating the photoresist etch step when an analysis of the interference patterns indicates that the predefined photoresist thickness is achieved, whereby the predefined photoresist thickness is greater than zero.

Abstract: A method for forming features in dielectric layers and opening barrier layers for a plurality of wafers and cleaning an etch chamber after processing and removing each wafer of the plurality of wafers is provided. A wafer of the plurality of wafers is placed into the etch chamber wherein the wafer has a barrier layer over the wafer and a dielectric layer over the barrier layer. The dielectric layer is etched. The barrier layer is opened. The wafer is removed from the etch chamber. A waferless automatic cleaning of the etch chamber without the wafer is provided. The waferless automatic cleaning comprises providing a waferless automatic cleaning gas comprising oxygen and nitrogen to the etch chamber and forming a waferless automatic cleaning plasma from the waferless automatic cleaning gas to clean the etch chamber.

Abstract: A method for controlling a photoresist etch step in a plasma processing chamber is disclosed. The photoresist etch step being configured to etch back a photoresist layer deposited on a substrate surface to a thinner photoresist layer having predefined photoresist thickness. The method includes etching the photoresist layer using a plasma etch process and detecting interference patterns coming from the photoresist layer. The method further includes terminating the photoresist etch step when an analysis of the interference patterns indicates that the predefined photoresist thickness is achieved, whereby the predefined photoresist thickness is greater than zero.

Abstract: A ternary Nb-Ta-S compound is provided having the atomic formula, Nb.sub.1.72 Ta.sub.3.28 S.sub.2, and exhibiting a layered structure in the sequence S-M3-M2-M1-M2-M3-S wherein S represents sulfur layers and M1, M2, and M3 represent Nb/Ta mixed metal layers. This sequence generates seven sheets stacked along the [001] direction of an approximate body centered cubic crystal structure with relatively weak sulfur-to-sulfur van der Waals type interactions between adjacent sulfur sheets and metal-to-metal bonding within and between adjacent mixed metal sheets.