Semiconductor device with contact structure

A semiconductor device, comprising:

• a bottom dielectric layer positioned on a substrate;
• a bottom conductive layer positioned in the bottom dielectric layer;
• an etch stop layer positioned on the bottom conductive layer, wherein the etch stop layer is a single layer made of silicon carbonitride, or silicon oxycarbide, wherein a height of the bottom conductive layer is equal to a thickness of the bottom dielectric layer, such that a bottom surface of the bottom conductive layer is in contact with a top surface of the substrate while a top surface of the bottom conductive layer is in contact with a bottom surface of the etch stop layer;
• a first inter-dielectric layer positioned on the etch stop layer, wherein the first inter-dielectric layer is a single layer, wherein the first inter-dielectric layer and the etch stop layer are made of different materials;
• and
• a contact structure comprising:
• a body portion positioned along the first inter-dielectric layer and extending to the etch stop layer, wherein a bottom surface of the body portion is positioned below a top surface of the etch stop layer;
• and
• a contact portion positioned in the etch stop layer, wherein the contact portion is extended from the body portion and is in contact with a portion of the top surface of the bottom conductive layer, wherein a height of the contact portion is less than a thickness of the etch stop layer;
• wherein a width of the body portion is greater than a width of the contact portion;
• wherein a height of the body portion is greater than a height of the bottom conductive layer;
• wherein a height of the contact portion is less than a height of the etch stop layer;
• wherein a width of the bottom conductive layer is greater than the width of the body portion of the contact structure.