Methods and apparatuses are described for integration of integrated circuit die and silicon-based trench capacitors using silicon-level connections to reduce connection lengths, parasitics and necessary capacitance magnitudes and volumes. A trench capacitor can be fabricated on silicon and mounted on or embedded in a chip or one or more sides of a through silicon interposer (TSI) for silicon-level connections to chip circuitry. Aspect ratio dependent, as opposed to trench diameter or trench depth dependent, trench capacitors formed by a dense array of high aspect ratio trenches with thin, high permittivity dielectric increase capacitance per unit area and volume, resulting in thin, high capacitance trench capacitors having thickness equal to or less than chip thickness.