Simultaneous STI and TSV Formation in IC Substrates

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Solution Overview

Problem

Current methods for manufacturing integrated circuits with shallow trench isolation and through-substrate vias are inefficient due to the need for multiple separate processing steps, which increase costs and resource utilization.

Innovation Solution

A method that simultaneously forms and fills shallow trench isolation and through-substrate via openings with insulating and conductive materials, using a common passivation and diffusion barrier layer, reducing the number of processing steps and tools required.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If separate processing steps are used for forming shallow trench isolation and through-substrate vias, then manufacturing precision can be maintained, but fabrication time and costs increase

Engineering Contradiction:
Improveisolation and via formation precisionVSAvoidfabrication time
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent combines the formation of shallow trench isolation openings and through-substrate via openings into a single simultaneous etching process. By using a unified mask pattern and etch process, both structures are created in one step rather than sequentially, reducing fabrication time while maintaining precision through controlled etch parameters and mask design.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mask layer is designed with preliminary patterns that define both the STI openings and TSV openings before etching begins. This preliminary patterning allows the etch process to simultaneously create both structures with correct dimensions and positions, eliminating the need for separate masking and etching steps for each structure.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If multiple separate processing steps are used for forming STI and TSV, then structural integrity can be ensured, but resource utilization decreases

Engineering Contradiction:
Improvestructural integrityVSAvoidresource utilization
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the formation processes of STI and TSV into a single simultaneous operation using unified masking and etching. This reduces the number of processing steps, mask layers, and alignment operations required, thereby improving resource utilization while maintaining structural integrity through controlled process parameters.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The mask layer serves multiple functions simultaneously: it defines both STI and TSV opening positions, controls their dimensions, and ensures proper spacing. This multi-functionality reduces the need for separate specialized masking steps for each structure type, improving manufacturing efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If simultaneous processing of STI and TSV openings is implemented, then fabrication efficiency improves, but process complexity increases

Engineering Contradiction:
Improvefabrication efficiencyVSAvoidprocess complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines STI and TSV formation into a single etch process with unified masking, reducing the total number of processing steps. While the simultaneous processing requires carefully designed mask patterns and controlled etch parameters, it eliminates multiple sequential steps, alignment operations, and intermediate inspections, thereby reducing overall process complexity despite the sophistication of the simultaneous etching itself.

Inventive Principle:
Principle #5Merging (Combining)

4Adaptability or versatility

If different dielectric materials are used for STI and TSV filling, then functional requirements are met, but manufacturing steps increase

Engineering Contradiction:
Improvefunctional adaptabilityVSAvoidmanufacturing steps
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent fills both STI openings and TSV openings with dielectric material in a single deposition step using the same material. This unified filling approach reduces manufacturing steps and simplifies the process while still allowing for functional differentiation through selective conductive plug formation in TSVs later, maintaining adaptability without increasing immediate manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2466634B1Integration of shallow trench isolation and through-substrate vias into integrated circuit designs
Publication Date: 2019.06.19 LSI CORP
  • EP2466634B1 patent drawingFigure 1
  • EP2466634B1 patent drawingFigure 2
  • EP2466634B1 patent drawingFigure 3A

AI summary

A method of manufacturing an IC, comprising providing a substrate having a first side and a second opposite side, forming a STI opening in the first side of the substrate and forming a partial TSV opening in the first side of the substrate and extending the partial TSV opening. The extended partial TSV opening is deeper into the substrate than the STI opening. The method also comprises filling the STI opening with a first solid material and filling the extended partial TSV opening with a second solid material. Neither the STI opening, the partial TSV opening, nor the extended partial TSV opening penetrate an outer surface of the second side of the substrate. At least either: the STI opening and the partial TSV opening are formed simultaneously, or, the STI opening and the extended partial TSV opening are filled simultaneously.