Methods of TSV formation for advanced packaging
The present disclosure relates to through-via structures with dielectric shielding of interconnections for advanced wafer level semiconductor packaging. The methods described herein enable the formation of high thickness dielectric shielding layers within low aspect ratio through-via structures, thus facilitating thin and small-form-factor package structures having high I/O density with improved bandwidth and power.
1. A method of forming a through-silicon via structure, comprising:
applying and patterning a first resist film on a first side of a silicon substrate;
etching the silicon substrate through the patterned first resist film to form a hole in the first side;
plating a conductive material over the first side of the silicon substrate, the conductive material extending through the hole;
grinding or polishing the first side of the silicon substrate, wherein the grinding or polishing removes the conductive material disposed outside of the hole;
applying and patterning a second resist film on the first side of the silicon substrate;
etching the silicon substrate through the patterned second resist film to form a trench in the first side, the trench surrounding the hole having the conductive material extending therethrough;
laminating a dielectric film onto the first side of the silicon substrate, the lamination of the dielectric film causing a dielectric material of the dielectric film to fill the trench; and
grinding or polishing the first side of the silicon substrate and a second side opposite the first side, wherein the grinding or polishing removes the dielectric film disposed outside of the trench, and wherein the grinding or polishing further exposes the conductive material and the dielectric material on the first side and the second side.
2. The method of claim 1 , wherein the trench has an annular shape.
3. The method of claim 1 , wherein the dielectric material comprises an epoxy resin having a ceramic filler.
4. The method of claim 3 , wherein the ceramic filler comprises one or more of aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ), silicon carbide (SiC), silicon nitride (Si 3 N 4 ), Sr 2 Ce 2 Ti 5 O 16 ceramics, zirconium silicate (ZrSiO 4 ), wollastonite (CaSiO 3 ), beryllium oxide (BeO), cerium dioxide (CeO 2 ), boron nitride (BN), calcium copper titanium oxide (CaCu 3 Ti 4 O 12 ), magnesium oxide (MgO), titanium dioxide (TiO 2 ), and zinc oxide (ZnO).
5. The method of claim 1 , wherein the conductive material is plated via electroless plating, or physical vapor deposition (PVD) and electrochemical deposition (ECD).
6. The method of claim 5 , wherein the conductive material comprises at least one of copper, aluminum, gold, nickel, silver, palladium, and tin.