Stress-Controlled Formation of Tin Hard Mask

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

• determining external stress to be exerted on a model TiN hard mask in a model semiconductor structure, the model semiconductor structure including:
• a model insulating layer and a plurality of model trenches defined into the model insulating layer thereby to define a plurality of interweaving model trench sidewalls, each of the model trench sidewalls including the model insulating layer, the model TiN hard mask formed over the model insulating layer, and a model anti-diffusion barrier film formed over the model TiN hard mask;
• determining a number of TiN sub-layers, and a duration of a plasma gas treatment to be performed in the formation of each of the TiN sub-layers, wherein the determination is made in such a way that when a TiN hard mask is formed in accordance with the TiN sub-layer number and the duration of a plasma gas treatment, the TiN hard mask will have an internal stress that counter-balances an external stress;
• providing a stack of layers including:
• a substrate;
• an etch stop layer formed over the substrate;
• and an insulating layer formed over the etch stop layer;
• and
• forming a TiN hard mask over the insulation layer, wherein the TiN hard mask comprises TiN sub-layers of the determined TiN sub-layer number, and wherein each of the TiN sub-layers is successively formed by depositing TiN mixed with chlorine, and treating the deposited TiN sub-layer with a plasma gas for the determined duration.

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

• providing a substrate including an insulating layer formed over an etch stop layer;
• and
• forming a titanium nitride (TiN) hard mask over the insulation layer, by sequentially performing the steps of:
• depositing a first layer of TiN mixed with chlorine;
• performing a first plasma gas treatment;
• depositing a second layer of TiN mixed with chlorine;
• and
• performing a second plasma gas treatment.