Agency for Science, Technology and Research

Mohanraj Soundarapandian

Ranganathan Nagarajan

Chirayarikathuveedu Premachandran Sankarapillai

A substrate having target transfer regions thereon is provided. A sacrificial wafer is coated with a polymer layer with low adhesion to metals. A conductive layer is coated on the polymer layer and covered with a photoresist layer which is patterned to provide openings to the conductive layer. Thin film and passive or active device structures are formed on the conductive layer within the openings. The substrate is bonded to the sacrificial wafer wherein the thin film and passive or active device structures and the photoresist layer provide the bonding and wherein the thin film and passive or active device structures contact the substrate at the target transfer regions. The photoresist is stripped in a high frequency agitation bath wherein the photoresist separates from the sacrificial wafer and wherein the thin film and passive or active device structures separate from the polymer layer to complete transfer bonding.

Method of forming through-wafer interconnects for vertical wafer level packaging

A wafer is provided having through-holes therein to form a through-hole via wafer. A substrate of a sacrificial wafer is provided. The substrate is coated with a polymer having low adhesion to metals. A conductive layer is deposited on the polymer. A photoresist layer is coated on the conductive layer. The through-hole via wafer is bonded to the sacrificial wafer wherein the photoresist layer provides the bonding. The photoresist exposed in the through-holes is developed away to expose the conductive layer. The through-holes are filled with a conductive material by electroplating the conductive layer. The photoresist is stripped in an ultrasonic bath wherein the photoresist separates from the through-hole wafer and wherein the filled through-holes separate from the polymer at an interface between the polymer and the conductive layer to complete separation of the through-hole via wafer from the sacrificial wafer.

Growing community of inventors

Singapore, Singapore

Mohanraj Soundarapandian