Method of Semiconductor Device Fabrication

A method for fabricating a semiconductor device, the method comprising:

• depositing a dielectric layer over a substrate;
• depositing a hard mask (HM) layer over the dielectric layer;
• forming a fin trench through the HM layer and the dielectric layer and extending down to the substrate;
• forming a semiconductor feature in the fin trench, wherein a top surface of the semiconductor feature is planar with a top surface of the HM layer;
• forming a sacrificial layer over the semiconductor feature and the HM layer;
• removing the sacrificial layer and the HM layer in a first region to expose a first subset of the semiconductor feature and the dielectric layer, wherein the sacrificial layer covers a second subset of the semiconductor feature and the HM layer in a second region;
• forming an interlayer dielectric (ILD) layer over the first subset of the semiconductor features and the exposed dielectric layer in the first region;
• and
• removing the sacrificial layer and the HM layer in the second region to expose upper portions of the second subset of the semiconductor features to form fin features.

A method for fabricating a semiconductor device, the method comprising:

• depositing a dielectric layer over a substrate;
• depositing a hard mask (HM) layer over the dielectric layer;
• forming a mandrel feature over the HM layer;
• forming the spacer along sidewall of the mandrel feature;
• selectively removing the mandrel feature;
• depositing the sacrificial layer over the spacer;
• etching back the sacrificial layer to expose the spacer;
• selectively removing the spacer to form an opening in the sacrificial layer;
• etching the HM layer and dielectric layer through the opening and extending etching down to the substrate to form a fin trench;
• forming a semiconductor feature in the fin trench;
• and
• removing the HM layer to expose an upper portion of the semiconductor feature to form fin features.