Methods and devices to reduce defects in dielectric stack structures

A method of reducing incidences of defects in a stack of dielectric layers formed by chemical vapor deposition, the method comprising:

• flowing a liquid silicon-and-oxygen-containing precursor material to an injection valve;
• vaporizing the liquid silicon-and-oxygen-containing precursor material in a carrier gas flowed through the injection valve;
• causing a reaction involving the vaporized liquid silicon-and-oxygen-containing precursor material to deposit a first dielectric layer;
• halting the flow of liquid silicon-and-oxygen-containing precursor material to the injection valve at a first time while maintaining a flow of the carrier gas to the injection valve;
• and
• halting the flow of carrier gas to the injection valve at a second time after the first time,
• wherein a delay between halting of the flow of liquid silicon-and-oxygen-containing precursor material to the injection valve and halting the flow of carrier gas to the injection valve vaporizes the liquid silicon-and-oxygen-containing precursor material remaining in the injection valve and reduces incidences of defects in the stack of dielectric layers caused by subsequent deposition of liquid silicon-and-oxygen-containing precursor material.