Aluminum-Containing Layers and Methods of Forming the Same

A method for depositing a layer on a substrate by atomic layer deposition in a plurality of cycles, comprising:

• providing a system comprising:
• a reactor,
• a flow rate sensor positioned at an inlet port leading to the reactor,
• a valve configured to control fluid communication between a gas source of a precursor and the inlet port, and
• a control system in electrical communication with the flow rate sensor and the valve;
• and
• controlling the valve according to a flow rate of the precursor measured by the flow rate sensor to maintain a constant amount of the precursor flowing into the reactor in each of the plurality of cycles.

An interconnect structure, comprising:

• a first interlayer dielectric layer on a semiconductor substrate;
• an etch stop layer on the first interlayer dielectric layer;
• and
• a second interlayer dielectric layer on the etch stop layer,
• wherein the etch stop layer comprises aluminum (Al) and nitrogen atom (N), and
• wherein the etch stop layer comprises an average density greater than 2.65 g/cm3 measured by X-ray reflectometry (XRR) throughout the etch stop layer.