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Method for QTM for assembly induced ILD failures using blanket dielectric films

IP.com Disclosure Number: IPCOM000007829D
Publication Date: 2002-Apr-25
Document File: 4 page(s) / 62K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a quick-turn monitor (QTM) for assembly-induced inter-layer dielectric (ILD) failures using blanket dielectric films. Benefits include improved reliability.

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Method for QTM for assembly induced ILD failures using blanket dielectric films

Disclosed is a method for a quick-turn monitor (QTM) for assembly-induced inter-layer dielectric (ILD) failures using blanket dielectric films. Benefits include improved reliability.

Background

              Conventionally,QTM solves the dilemma between the requirement for evaluating die/packaging interaction before selecting ILD materials and integration process development. If the die/packaging evaluation is based on fully integrated interconnects, the amount of process development involved significantly limits the number of dielectric materials.

      Two conventional approaches handle this die/packaging evaluation. One waits for the full integration process to be developed before the evaluation. The other (see Figure 1) is based on single level metal (SLM) structures integrated with ILD materials. The die is bonded to the package using a homogeneous continuous adhesive layer to simulate the global stress environment. The die can be either bumped or bumpless. However, the absence of joints at bumps means that this QTM cannot capture failures associated with the stress concentration induced by the bump during packaging. Furthermore, limited patterning support is still required to generate SLM structures integrated with a material set.

              The conventional dual-damascene process dictates that the end system (ES) to the lower metal/ILD interface is significantly impacted by various integration processes. The ES to the top ILD/via interface is less sensitive to the presence of metal due to low via density and the absence of additional process steps, such as chemical mechanical polishing (CMP) ash/clean.

              Conventional leading failure modes are associated with stress concentration under the bump. Bumps without SiN passivation openings reproduce ILD failure modes as the conventional bumps contact metal pads. Fracture patterns depend on the bump footprint rather than the metal layout in the ILD. Bumps without SiN passivation openings reproduce ILD failure modes as conventional bumps contact metal pads.

General description

      The disclosed method isa test scheme for assessing assembly-induced ILD failures as a QTM for the fabrication/assembly process and for dielectric material selection. The scheme is designed to evaluate dielectric films in their blanket forms and capture leading failure modes observed in fully integrated cases. This procedure identifies early ILD/assembly interaction independently of integration process development.

              The key method elements include the concept of substituting one metal layer in existing interconnect stacks with a blanket film of dielectric and/or etch stop material. The uniqueness of this design is the insertion of materials in the conventional in...