Conductive Mask Etching for Semiconductor Contact Stability

Solution Overview

Problem

Conventional capacitive pressure sensors suffer from electrical instability due to etch byproducts adhering to the sidewalls and bottoms of openings during the fabrication process, leading to increased contact resistance and degraded sensor performance.

Innovation Solution

A semiconductor fabrication method where a conductive mask layer is used instead of a dielectric mask, reducing the formation of hard-to-remove etch byproducts and allowing for easier cleaning, which results in improved electrical stability of the conductive plugs and simplifies the fabrication process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a dielectric mask layer is used during etching, then the mask provides sufficient structural support, but etch byproducts adhere to the sidewalls and bottoms of openings causing electrical instability

Engineering Contradiction:

Improvemask layer structural supportVSAvoidelectrical stability

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent changes the material parameter of the mask layer from dielectric to conductive material. This parameter change fundamentally alters the etching behavior, reducing the formation of hard-to-remove etch byproducts and enabling easier cleaning of the openings, thereby improving electrical stability while maintaining sufficient structural support during the etching process.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If a dielectric mask layer is used, then masking is effective, but cleaning etch byproducts becomes difficult and time-consuming

Engineering Contradiction:

Improvemasking effectivenessVSAvoidcleaning time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent changes the material parameter of the mask layer from dielectric to conductive material. This parameter change fundamentally alters the etching behavior, reducing the formation of hard-to-remove etch byproducts and enabling easier cleaning of the openings, thereby improving electrical stability while maintaining sufficient structural support during the etching process.

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If conventional etching processes are used, then openings are formed, but etch byproducts cause increased contact resistance

Engineering Contradiction:

Improveopening formationVSAvoidcontact resistance

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the material parameter of the mask layer from dielectric to conductive material. This parameter change fundamentally alters the etching behavior, reducing the formation of hard-to-remove etch byproducts and enabling easier cleaning of the openings, thereby improving electrical stability while maintaining sufficient structural support during the etching process.

Inventive Principle:

Principle #35Parameter changes

4Reliability

If multiple cleaning steps are performed, then etch byproducts are removed, but the fabrication process becomes more complex

Engineering Contradiction:

Improvebyproduct removalVSAvoidfabrication process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the material parameter of the mask layer from dielectric to conductive material. This parameter change fundamentally alters the etching behavior, reducing the formation of hard-to-remove etch byproducts and enabling easier cleaning of the openings, thereby improving electrical stability while maintaining sufficient structural support during the etching process.

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method ensures better electrical stability and reduced damage to conductive plugs, enhancing the performance and reliability of the semiconductor devices by minimizing the impact of etch byproducts and allowing the conductive mask layer to function as part of the device.

Implementation Method 1

The first mask layer and the sacrificial layer are etched until a surface of the first electrode layer is exposed to form openings through the first mask layer and the sacrificial layer

Methodology Applied

Scientific EffectEtching:

Implementation Method 2

A cleaning process is performed to remove etch byproducts adhered to a surface of the first mask layer and adhered to sidewalls and bottom surfaces of the openings

Methodology Applied

Scientific EffectCleaning:

Implementation Method 3

Conductive plugs are formed in the openings after the cleaning process

Methodology Applied

Scientific EffectConductive plug formation:

Data Source

PatentUS9875965B2Semiconductor device

Publication Date: 2018.01.23 SEMICON MFG INT (SHANGHAI) CORP

AI summary

Semiconductor devices and fabrication methods are provided. In a semiconductor device, a semiconductor substrate includes a first electrode layer having a top surface coplanar with a top surface of the semiconductor substrate. A sacrificial layer is formed on the semiconductor substrate and the first electrode layer. A first mask layer made of a conductive material is formed on the sacrificial layer. The first mask layer and the sacrificial layer are etched until a surface of the first electrode layer is exposed to form openings through the first mask layer and the sacrificial layer. A cleaning process is performed to remove etch byproducts adhered to a surface of the first mask layer and adhered to sidewalls and bottom surfaces of the openings. Conductive plugs are formed in the openings after the cleaning process.