Semiconductor Pad Etching for Dicing Yield Improvement
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Solution Overview
Problem
The challenge in semiconductor device manufacturing is the occurrence of scattering dusts and chipping due to clogging during the dicing process, which leads to a decrease in yields and an increase in costs, particularly when processing back-side-illuminated solid-state image pickup elements where the pad is positioned deeper than the substrate top face, causing resist collapse and pattern errors.
Innovation Solution
A method involving multiple stages of etching is employed to connect and separate the pad and scribe line regions, ensuring that the etching process forms opening portions that link both regions, thereby removing the linking region by etching, which helps in preventing dust scattering and peel-off of the undercoat from the passivation film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If etching for opening pad and scribe line is conducted simultaneously, then manufacturing efficiency is improved, but resist collapse and pattern errors occur
Solution Approach 1:
The etching process is divided into multiple stages: first etching the pad opening, then etching the scribe line opening separately. This segmentation prevents resist collapse by avoiding the need to maintain narrow spaces between closely spaced openings throughout the entire etching process, while still achieving the goal of processing both regions efficiently through sequential operations.
Solution Approach 2:
The pad opening etching is performed first as a preliminary action before scribe line etching. This preliminary removal of material creates larger spacing between openings in subsequent steps, preventing resist collapse during the second etching operation while maintaining manufacturing efficiency through the staged approach.
2Area of moving object
If pad and scribe line are placed close to each other, then chip size is reduced, but resist collapse and pattern errors occur
Solution Approach 1:
The manufacturing process is segmented into sequential etching steps for pad and scribe line regions. This allows close placement of pad and scribe line in the final chip design while avoiding resist collapse during manufacturing, as each region is processed separately when openings are larger and more stable.
Solution Approach 2:
By performing pad opening etching first as a preliminary action, the structure is prepared to accommodate close spacing between pad and scribe line. The first etching creates a configuration that prevents resist collapse in subsequent steps, enabling minimal spacing while maintaining pattern accuracy.
3Device complexity
If dicing is conducted without removing films in scribe line region, then manufacturing process is simplified, but dicing blade clogging and chipping occur
Solution Approach 1:
The etching of films in the scribe line region is performed as a preliminary action before dicing. This preliminary removal of SiO2, SiN, and other films prevents blade clogging and chipping during subsequent dicing operations, while the etching is integrated into the existing pad opening process to minimize additional manufacturing complexity.
4Manufacturing precision
If etching is conducted to remove films in scribe line region, then dicing quality is improved, but peel-off of undercoat from passivation film occurs
Solution Approach 1:
The etching process is applied locally and selectively to specific regions and depth levels. The pad opening etching and scribe line etching are performed with controlled parameters that remove films only where needed while preserving the stability of the passivation film and its undercoat in other regions, preventing peel-off while improving dicing quality.
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
This approach increases manufacturing yields and reduces costs by effectively suppressing dust scattering and chipping during the dicing process, ensuring the semiconductor devices are produced with improved quality and reduced defects.
Implementation Method 1
when etching for opening the pad is divisionally conducted a plurality of times on a layer basis, a part of a plurality of layers to be a unit to be etched is subjected to etching for opening a scribe line portion simultaneously with the etching for forming an opening of the pad
Data Source
AI summary
The present technology relates to a semiconductor device that suppresses scattering dusts caused by dicing, chipping due to clogging, and further suppresses peel-off of an undercoat from a passivation film, thereby improving yields in manufacturing to realize cost reduction and a method for manufacturing the semiconductor device, a solid-state image pickup element, an image pickup device, and an electronic apparatus. In a step of exposing a pad by etching, when etching a lens material layer as an uppermost layer and a passivation layer, a pad portion and a blade region to be cut by a blade at the time of dicing are simultaneously etched, while a part of a region including both portions and a part therebetween or all the region on the lump, is simultaneously etched. Thereafter, in a layer of the semiconductor substrate under the lens material layer, only the pad portion is etched to expose the pad.