Semiconductor Conductive Layer Erosion Protection via Extended Masking

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Solution Overview

Problem

Conventional semiconductor device manufacturing methods require additional steps and suffer from quality decline due to resist residue, especially in three-dimensional packaging techniques, where the resist can flow into narrow gaps and be difficult to remove, leading to erosion issues and increased production costs.

Innovation Solution

The method involves forming a conductive member with a protective film and using a resist that is patterned to exclude areas where the conductive layers are to be formed, followed by a mask metal layer to protect against etching solutions, allowing for the removal of the resist without additional steps and preventing erosion, thereby improving adhesiveness and conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the conventional method of covering the connecting terminal or electrode pad section with resist to prevent erosion is used, then the connecting terminal or electrode pad section is protected from erosion by wet-etching solution, but additional photolithography steps are required and resist material must be applied, increasing production cost and process complexity

Engineering Contradiction:
Improveprotection from erosionVSAvoidprocess steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The conductive layer is formed to extend beyond the connecting terminal or electrode pad section before etching the through-hole. This preliminary extension creates a built-in protective barrier that prevents erosion of the connecting terminal or electrode pad section during subsequent wet-etching processes, eliminating the need for additional resist coating steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The protective function is merged with the conductive layer itself. Instead of using a separate resist layer for protection, the conductive layer is deliberately designed to extend beyond the terminal or pad section, serving both as the electrical conductor and as the protective barrier against etching solution.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If resist is used to cover the connecting terminal or electrode pad section, then protection from erosion is achieved, but resist residue can flow into narrow gaps and be difficult to remove, causing quality decline

Engineering Contradiction:
Improveprotection from erosionVSAvoidquality
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The resist material is completely removed from the process. The protective function previously performed by resist is transferred to the conductive layer itself, which is designed to extend beyond the connecting terminal or electrode pad section. This extraction of resist eliminates the problem of resist residue flowing into narrow gaps and causing quality issues.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The extended conductive layer serves as a temporary protective barrier during etching, similar to how resist would function, but without the drawbacks of resist residue. The conductive layer is permanently retained as part of the device structure while providing the necessary protection during manufacturing.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Reliability

If additional photolithography steps are added to cover the connecting terminal or electrode pad section with resist, then protection from erosion is improved, but production cost increases

Engineering Contradiction:
Improveprotection from erosionVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The conductive layer is formed with extended dimensions in advance, before the etching process. This preliminary design ensures that the connecting terminal or electrode pad section is protected during etching without requiring additional photolithography steps, thereby reducing production cost while maintaining reliability.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2546868B1Process for production of semiconductor device
Publication Date: 2020.01.08 INVENSAS CORP
  • EP2546868B1 patent drawingFigure 1
  • EP2546868B1 patent drawingFigure 2A~2B
  • EP2546868B1 patent drawingFigure 2C~2D

AI summary

Abase conductive member (207) is formed on a surface and in a hole section (205) of a substrate (201), and a resist (208) is formed on a part of the base conductive member (207) in which a conductive layer (209, 210) is not to be formed. The conductive layer (209, 210) is formed on a part except for the part in which the resist (208) has been formed, and a mask metal (212) is formed on the conductive layer (209, 210). Then, the resist (208) is removed, and the base conductive member (207) is etched using the mask metal (212) as a mask to form the conductive layer (209, 210) into a predetermined shape.