Queue time

The result will be minimum work-in-process (WIP) through the elimination of queue time and a significant reduction in the cost of quality when compared to the more conventional approaches to manufacturing used in recent years. However, the new approaches to manufacturing demand three things from the raw materi-... 

CPU utilization Cache memory utilization Disk capacity utilization Interactive response time Number of transactions per time unit Average job waiting time Print queue times I/O load... 

Calculate the total queue times and the total time for the process, and display this in a time line at the bottom of the chart. This distinctive time line is found on all Value Stream Maps, and at a glance it shows how much of the total elapsed time (lead time) is value-added. 

It should be noted that even if there are no shorts detected by electrical testing, the onset of such corrosion induces topography and weakens the interface with the SiCN capping layer, causing reliability problems. Evidence of this is presented by Liniger et al. (2010) in Figure 4.27 through time-dependent dielectric breakdown (TDDB) characterization of the effect of queue time. It can be seen that as queue time is increased, the time required for 50% of the structures to fail with a short under the applied electric field decreases. 

Other types of defects related to chemical attack are Cu nodules or dendrites (DE) as exhibited in Figure 17.15(e). Previous works identify the DE as CuOx particulates formed after certain queue time post-CMP [19—21]. Galvanic corrosion is responsible for the formation of DE as shown in Figure 17.16 [19]. In the presence of wet slurry or... 

Corrosion and DE defects from CMP are known to result in resistance increase and short circuits. They can also induce loss in TDDB and electromigration lifetime [19,23—26]. An example of post-Cu CMP queue time effect on dielectric breakdown voltage is illustrated in Figure 17.17. 

Figure 17.17 Impact of post-Cu CMP queue time on dielectric breakdown dielectric breakdown voltage decreases as post-Cu CMP queue time increases [24].

Different from PR/FM and scratches, one unique characteristic of HM, DE, and corrosion-related defects is their time dependence the longer the wafer remains in the ambient, the more corrosion defects there will be. Such queue time effects on defects begin immediately after barrier metal is deposited and will not stop until the cap layer is deposited on the post-CMP Cu surface. HM defects are found to increase with increasing queue time between anneal and CMP as well as between CMP and cap [22]. The hndings reveal the time dependence nature of corrosive attack that can lead to HM defects. 

Similarly, Cu oxide DE growth post-CMP exhibits queue time effects as previous studies have indicated [19,20,22]. One study pointed out that a certain amount of lag time between plating and furnace anneal can help extend the post-CMP queue time DE free for up to 144 h [22]. The plating-anneal lag time dependence of DE implies that room temperature self-annealing of Cu during the lag time can alter the Cu microstructure to the extent that it enhances surface passivation and/or reduces Cu oxide... 

Queue time violation Queue time violation, in air N2 purge... 

Materials management Value/amount of work in progress Customer queue time Supplier performance... 

Queue Time The time a product spends in a line awaiting the next design, order processing, or fabrication step. 

Throughput Time The time required for a product to proceed from concept to launch, order to delivery, or raw materials into the hands of the customer. It includes both processing and queue time. 

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