Through-substrate via and method of making same

A via fabrication method comprising:

• disposing a masking layer on a backside of a semiconductor substrate;
• performing photolithographic processing to form an opening in the masking layer;
• performing first dry etching to form a through-substrate via (TSV) opening aligned with the opening in the masking layer, the TSV opening passing through the semiconductor substrate from the backside of the semiconductor substrate to a frontside of the semiconductor substrate, the TSV opening being aligned with a conductive region disposed on the frontside of the semiconductor substrate;
• disposing a dielectric layer on a sidewall and a bottom of the TSV opening;
• performing second dry etching to remove the dielectric layer from the bottom of the TSV opening and access the conductive region disposed on the frontside of the semiconductor substrate, the second dry etching not removing at least a portion of the dielectric layer disposed on the sidewall of the TSV opening;
• after the second dry etching, performing electro-chemical plating to form a conductive TSV which fills the TSV opening and contacts the conductive region disposed on the frontside of the semiconductor substrate;
• and
• performing chemical mechanical polishing to remove excess conductive material disposed on the backside of the semiconductor substrate by the electro-chemical plating.