Strain relief trenches for epitaxial growth

A method, comprising:

• forming a photoresist layer over a substrate;
• exposing the photoresist layer to form a pattern in the photoresist layer;
• forming, using the pattern in the photoresist layer, a plurality of trenches in the substrate,
• wherein a first trench, of the plurality of trenches, is formed to have a different width-to-height aspect ratio than a second trench of the plurality of trenches,
• wherein the first trench is formed to have a different width than the second trench,
• wherein the plurality of trenches are formed to have tapered walls,
• wherein a first tapered wall, of the tapered walls, associated with the first trench has a different wall angle from a second tapered wall of the tapered walls, associated with the second trench, and
• wherein a location of the first tapered wall relative to the first trench corresponds to a location of the second tapered wall relative to the second trench;
• and
• growing an epitaxial layer in the plurality of trenches,
• wherein a first portion of the epitaxial layer is grown in the first trench and a second portion of the epitaxial layer is grown in the second trench, and
• wherein the first portion of the epitaxial layer and the second portion of the epitaxial layer are grown to form isolated islands of epitaxial growth.