Systems and methods for multi-height interconnect structures for a semiconductor device are provided herein. The multi-height interconnect structure generally includes a primary level semiconductor die having a primary conductive pillar and a secondary conductive pillar, where the primary conductive pillar has a greater height than the secondary conductive pillar. The semiconductor device may further include a substrate electrically coupled to the primary level semiconductor die through the primary conductive pillar and a secondary level semiconductor die electrically coupled to the primary level semiconductor die through the secondary conductive pillar. The multi-height pillars may be formed using a single photoresist mask or multiple photoresist masks. In some configurations, the primary and secondary conductive pillars may be arranged on only the front-side of the dies and/or substrate.

A method for fabricating a resist structure is presented. The method includes preparing a substrate on which plural conductive pads are formed; and patterning a lower resist to form plural lower cavities. The lower resist is deposited above the substrate. Each of the plural lower cavities are located above a corresponding one of the plural conductive pads. Additionally, the method includes patterning an upper resist to form plural upper cavities. The upper resist is deposited on the lower resist. Each of the plural upper cavities are located on a corresponding one of the plural lower cavities and have a diameter larger than a diameter of the corresponding one of the plural lower cavities.

A method for forming a semiconductor structure is provided. The method includes forming a seed layer over a substrate and forming a first mask layer over the seed layer. The method also includes forming a first trench and a second trench in the first mask layer and forming a first conductive material in the first trench and the second trench. The method further includes forming a second mask layer in the first trench and over the first conductive material, and forming a second conductive material in the second trench and on the first conductive material. A first conductive connector is formed in the first trench with a first height, a second conductive connector is formed in the second trench with a second height, and the second height is greater than the first height.

An embodiment bump on trace (BOT) structure includes a contact element supported by an integrated circuit, an under bump metallurgy (UBM) feature electrically coupled to the contact element, a metal ladder bump mounted on the under bump metallurgy feature, the metal ladder bump having a first tapering profile, and a substrate trace mounted on a substrate, the substrate trace having a second tapering profile and coupled to the metal ladder bump through direct metal-to-metal bonding. An embodiment chip-to-chip structure may be fabricated in a similar fashion.

A substrate or semiconductor device, semiconductor device assembly, and method of forming a semiconductor device assembly that includes a barrier on a solder cup. The semiconductor device assembly includes a substrate disposed over another substrate. At least one solder cup extends from one substrate towards an under bump metal (UBM) on the other substrate. The barrier on the exterior of the solder cup may be a standoff to control a bond line between the substrates. The barrier may reduce solder bridging during the formation of a semiconductor device assembly. The barrier may help to align the solder cup with a UBM when forming a semiconductor device assembly and may reduce misalignment due to lateral movement of substrates and/or semiconductor devices.

A semiconductor package includes a semiconductor chip comprising a first surface and a second surface, a redistribution layer on the first surface of the semiconductor chip, an under bump metal (UBM) layer on the redistribution layer, and a solder bump on the UBM layer, and the solder bump covers both outer side surfaces of the UBM layer.

Various semiconductor chips and packages are disclosed. In one aspect, an apparatus is provided that includes a semiconductor chip that has a side, and plural conductive pillars on the side. Each of the conductive pillars includes a pillar portion that has an exposed shoulder facing away from the semiconductor chip. The shoulder provides a wetting surface to attract melted solder. The pillar portion has a first lateral dimension at the shoulder. A solder cap is positioned on the pillar portion. The solder cap has a second lateral dimension smaller than the first lateral dimension.

A semiconductor device includes a conductive pattern disposed over a semiconductor substrate, and an interconnect structure disposed over the conductive pattern. The semiconductor device also includes an interconnect liner formed between the interconnect structure and the conductive pattern and surrounding the interconnect structure. The inner sidewall surfaces of the interconnect liner are in direct contact with the interconnect structure, and a maximum distance between outer sidewall surfaces of the interconnect liner is greater than a width of the conductive pattern. The semiconductor device further includes a semiconductor die bonded to the semiconductor substrate. The semiconductor die includes a conductive pad facing the interconnect structure, wherein the conductive pad is electrically connected to the conductive pattern.

Techniques for simultaneously plating features of varying sizes on a semiconductor substrate are provided. In one aspect, a method for electroplating includes: placing a shield over a wafer, offset from a surface of the wafer, which covers portions of the wafer and leaves other portions of the wafer uncovered; and depositing at least one metal onto the wafer by electroplating to simultaneously form metallurgical features of varying sizes on the wafer based on the shield altering local deposition rates for the portions of the wafer covered by the shield. An electroplating apparatus is also provided.

The present technology is directed to manufacturing collars for under-bump metal (UBM) structures for die-to-die and/or package-to-package interconnects and associated systems. A semiconductor die includes a semiconductor material having solid-state components and an interconnect extending at least partially through the semiconductor material. An under-bump metal (UBM) structure is formed over the semiconductor material and is electrically coupled to corresponding interconnects. A collar surrounds at least a portion of the side surface of the UBM structure, and a solder material is disposed over the top surface of the UBM structure.