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CN-224218812-U - TiW-NiV double-layer UBM-based aluminum nickel tin silver bump interconnection structure

CN224218812UCN 224218812 UCN224218812 UCN 224218812UCN-224218812-U

Abstract

The utility model discloses an aluminum nickel tin silver bump interconnection structure based on a TiW-NiV double-layer UBM, which relates to the technical field of semiconductor packaging and comprises a substrate, a bonding pad, a double-layer UBM structure and an aluminum nickel tin silver bump which are sequentially arranged from bottom to top, wherein the double-layer UBM structure comprises a titanium tungsten layer tightly attached to the surface of the bonding pad and a nickel vanadium layer covering the surface of one side of the titanium tungsten layer far away from the bonding pad, the W atomic ratio of the side of the nickel vanadium layer is 80-90 at%, the aluminum nickel tin silver bump comprises a high-purity aluminum layer, a nickel barrier layer and a Sn-3.5Ag bonding layer which are sequentially stacked on the surface of one side of the nickel vanadium layer far away from the titanium tungsten layer, and gradient components of the titanium tungsten layer and the nickel vanadium layer are designed and matched in thickness to form a composite layer with high adhesiveness and strong diffusion barrier, so that stable connection between the bonding pad and the bump layer is ensured.

Inventors

  • LIN YUWEI
  • ZHANG YANSHUO
  • DENG GUANGSHENG
  • LIU YULI
  • Bi Zhongquan
  • Meng Zhonglv

Assignees

  • 广西华芯振邦半导体有限公司

Dates

Publication Date
20260508
Application Date
20250516

Claims (6)

  1. 1. The TiW-NiV double-layer UBM-based aluminum nickel tin silver bump interconnection structure is characterized by comprising a substrate, a bonding pad, a double-layer UBM structure and an aluminum nickel tin silver bump which are sequentially arranged from bottom to top, wherein the double-layer UBM structure comprises a titanium tungsten layer (104) tightly attached to the surface of the bonding pad and a nickel vanadium layer (105) covered on one side surface of the titanium tungsten layer (104) far away from the bonding pad, and the aluminum nickel tin silver bump comprises a high-purity aluminum layer (106), a nickel barrier layer (107) and an Sn-3.5Ag bonding layer (108) sequentially stacked on one side surface of the nickel vanadium layer (105) far away from the titanium tungsten layer (104).
  2. 2. The AlNiSn-Ag bump interconnection structure based on the TiW-NiV double-layer UBM of claim 1, wherein the high-purity aluminum layer (106) is 2-3 μm thick and has a purity of not less than 99.9%, the nickel barrier layer (107) is 0.8-1 μm thick, and the Sn-3.5Ag bonding layer (108) is 4-6 μm thick.
  3. 3. The aluminum nickel tin silver bump interconnection structure based on the TiW-NiV double-layer UBM is characterized in that the substrate is an 8-12 inch silicon wafer, the bonding pad is an aluminum bonding pad with the thickness of 1-2 microns or a copper bonding pad with the thickness of 3-5 microns, when the bonding pad is a copper bonding pad, an aluminum transition layer with the thickness of 1 micron is arranged between the copper bonding pad and a titanium tungsten layer (104), the aluminum transition layer is closely attached to the surface of the copper bonding pad, and the titanium tungsten layer (104) covers the surface of one side of the aluminum transition layer far away from the copper bonding pad.
  4. 4. The aluminum nickel tin silver bump interconnection structure based on the TiW-NiV double-layer UBM is characterized in that one side surface of a titanium tungsten layer (104) close to a bonding pad is completely attached to the surface of an aluminum transition layer to form a continuous barrier layer, a nickel vanadium layer (105) is completely covered on one side surface of the titanium tungsten layer (104) far away from the bonding pad, a tight metallurgical bonding interface is formed between the nickel vanadium layer (105) and the titanium tungsten layer (104), a high-purity aluminum layer (106) is completely covered on one side surface of the nickel vanadium layer (105) far away from the titanium tungsten layer (104), a nickel barrier layer (107) is completely covered on one side surface of the high-purity aluminum layer far away from the nickel vanadium layer (105), and a Sn-3.5Ag bonding layer (108) is completely covered on one side surface of the nickel barrier layer (107) far away from the high-purity aluminum layer (106) to form a five-layer bump structure which is sequentially overlapped from bottom to top.
  5. 5. The aluminum nickel tin silver bump interconnection structure based on the TiW-NiV double-layer UBM is characterized in that the nickel barrier layer (107) is of a nanocrystalline structure, crystal grain sizes are uniformly distributed, flat interfaces are formed among the high-purity aluminum layer (106), the nickel barrier layer (107) and the Sn-3.5Ag bonding layer (108), the transverse dimensions of the three-layer structure are consistent, the three-layer structure is matched with the transverse dimension of the nickel vanadium layer (105) below, and the upper surface of the Sn-3.5Ag bonding layer (108) forms a hemispherical surface for welding.
  6. 6. The AlNiSn-Ag bump interconnection structure based on the TiW-NiV double-layer UBM is characterized in that the titanium tungsten layer (104), the nickel vanadium layer (105), the high-purity aluminum layer (106), the nickel barrier layer (107) and the Sn-3.5Ag bonding layer (108) are all continuous film layers, no gaps exist among the layers and are tightly attached, the transverse dimension of the double-layer UBM structure is consistent with that of a bonding pad, the transverse dimension of the AlNiSn-Ag bump is consistent with that of the double-layer UBM structure, an up-down aligned stacked structure is formed, and the central axes of the substrate, the bonding pad, the double-layer UBM structure and the AlNiSn-Ag bump are coincident.

Description

TiW-NiV double-layer UBM-based aluminum nickel tin silver bump interconnection structure Technical Field The utility model particularly relates to the technical field of semiconductor packaging, in particular to an aluminum nickel tin silver bump interconnection structure based on a TiW-NiV double-layer UBM. Background In the field of semiconductor packaging, reliability and stability of bump interconnect structures are critical. The traditional copper nickel tin (Cu-Ni-Sn) bump has the problems of too thick interfacial intermetallic compound (IMC), insufficient electromigration performance, complex process and the like, while the aluminum-based bump has the advantages of cost and density, but has the advantages of interface diffusion control and mechanical property to be improved. The existing UBM layer (such as a single metal layer) is difficult to meet the requirements of high adhesiveness, strong diffusion barrier and good wettability, so that the problems of tin segregation, insufficient interface binding force and the like easily occur in the high-temperature reflow soldering process of the bump interconnection structure, and the reliability of the integrated circuit package is seriously affected. With the development of integrated circuits toward high density and high power, a new bump interconnection structure with optimized structure, distinct layers and balanced performance is needed to solve the problems of interface stability, thermo-mechanical matching, material cost and the like in the prior art. Disclosure of utility model The utility model aims to provide an aluminum nickel tin silver bump interconnection structure based on a TIW/NiV double-layer UBM, wherein in the device, gradient components of a titanium tungsten layer and a nickel vanadium layer are designed and matched with each other in thickness to form a composite layer with high adhesiveness and strong diffusion barrier, and stable connection with a bonding pad and a bump layer is ensured, so that the problems of the background technology are solved. In order to achieve the above purpose, the present utility model provides the following technical solutions: The aluminum nickel tin silver bump interconnection structure based on the TiW-NiV double-layer UBM comprises a substrate, a bonding pad, a double-layer UBM structure and an aluminum nickel tin silver bump which are sequentially arranged from bottom to top, wherein the double-layer UBM structure comprises a titanium tungsten layer tightly attached to the surface of the bonding pad and a nickel vanadium layer covered on the surface of one side of the titanium tungsten layer far away from the bonding pad, and the aluminum nickel tin silver bump comprises a high-purity aluminum layer, a nickel barrier layer and an Sn-3.5Ag bonding layer which are sequentially stacked on the surface of one side of the nickel vanadium layer far away from the titanium tungsten layer; As a further technical scheme of the utility model, the thickness of the titanium-tungsten layer is 0.15-0.25 mu m, the components of the titanium-tungsten layer are changed in a gradient manner from the bonding pad side to the nickel-vanadium layer side, the Ti atom proportion on the bonding pad side is 20-30 at%, the W atom proportion on the nickel-vanadium layer side is 80-90 at%, the thickness of the nickel-vanadium layer is 0.8-1.5 mu m, and the nickel-vanadium layer consists of 88-92% of Ni and 8-12% of V by mass percent. As a further technical scheme of the utility model, the thickness of the high-purity aluminum layer is 2-3 mu m, the purity is not lower than 99.9%, the thickness of the nickel barrier layer is 0.8-1 mu m, and the thickness of the Sn-3.5Ag bonding layer is 4-6 mu m. According to the technical scheme, the substrate is a silicon wafer with the thickness of 8-12 inches, the bonding pad is arranged on the surface of the silicon wafer, the bonding pad is an aluminum bonding pad with the thickness of 1-2 microns or a copper bonding pad with the thickness of 3-5 microns, when the bonding pad is a copper bonding pad, an aluminum transition layer with the thickness of 1 micron is arranged between the copper bonding pad and a titanium tungsten layer, the aluminum transition layer is closely attached to the surface of the copper bonding pad, and the titanium tungsten layer covers the surface of one side of the aluminum transition layer far away from the copper bonding pad. According to the technical scheme, one side surface of the titanium tungsten layer, which is close to the bonding pad, is completely attached to the surface of the aluminum transition layer to form a continuous barrier layer, the nickel vanadium layer is completely covered on one side surface of the titanium tungsten layer, which is far away from the bonding pad, and a tight metallurgical bonding interface is formed between the nickel vanadium layer and the titanium tungsten layer; as a further technical scheme of the utility model, the nick