Apparatus and methods for dielectric gap fill evaluations are provided. In one example, a method can comprise providing a gap fill substrate over one or more interlayer dielectric trenches of a dielectric layer and over a first material located in the one or more interlayer dielectric trenches. The method can also comprise depositing a gap fill candidate material within one or more gap fill substrate trenches of the gap fill substrate. Furthermore, the method can comprise etching the gap fill candidate material until a void within the first material is identified. Additionally, the method can comprise filling the one or more gap fill substrate trenches with a second material to form one or more contacts with the first material to measure a leakage current of one or more pitches.