Abstract: A first metal interconnect structure embedded in a first dielectric material layer includes a first metallic nitride liner containing a first conductive metal nitride and a first metallic fill material portion. A second metal interconnect structure embedded in a second dielectric material layer overlies the first dielectric material layer. The second metal interconnect structure includes a pillar portion having a straight sidewall and a foot portion adjoined to a bottom periphery of the pillar portion and laterally protruding from the bottom periphery of the pillar portion. The foot portion can be formed by oxidizing a top surface of the first metallic fill material portion, removing the oxidized portion after formation of a cavity through the second dielectric material layer, and depositing a second metallic nitride liner in a volume from which the oxidized portion is removed.

Abstract: A first metal interconnect structure embedded in a first dielectric material layer includes a first metallic nitride liner containing a first conductive metal nitride and a first metallic fill material portion. A second metal interconnect structure embedded in a second dielectric material layer overlies the first dielectric material layer. The second metal interconnect structure includes a pillar portion having a straight sidewall and a foot portion adjoined to a bottom periphery of the pillar portion and laterally protruding from the bottom periphery of the pillar portion. The foot portion can be formed by oxidizing a top surface of the first metallic fill material portion, removing the oxidized portion after formation of a cavity through the second dielectric material layer, and depositing a second metallic nitride liner in a volume from which the oxidized portion is removed.

Abstract: The longest possible sleep time is selected while data missing is prevented in a PON system by referring to the link speeds and the queue buffer capacities of an OLT and ONUs. The OLT calculates a first sleep time candidate based on a first link speed at which the OLT communicates with an upper network and the capacity of an unused area of a first queue buffer where downstream data is held for each of the destination ONUs. Each of the ONUs calculates a second sleep time candidate based on a second link speed at which each of the ONUs communicates with a communication terminal and the capacity of an unused area of a second queue buffer where upstream data bound for the OLT is held. The smaller sleep time is determined and used to change one of the ONUs to a sleep mode.

Abstract: The longest possible sleep time is selected while data missing is prevented in a PON system by referring to the link speeds and the queue buffer capacities of an OLT and ONUs. The OLT calculates a first sleep time candidate based on a first link speed at which the OLT communicates with an upper network and the capacity of an unused area of a first queue buffer where downstream data is held for each of the destination ONUs. Each of the ONUs calculates a second sleep time candidate based on a second link speed at which each of the ONUs communicates with a communication terminal and the capacity of an unused area of a second queue buffer where upstream data bound for the OLT is held. The smaller sleep time is determined and used to change one of the ONUs to a sleep mode.