Through-Substrate Insulating Film Patterning for Precise Electrodes
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Solution Overview
Problem
The existing wafer level chip size package (CSP) for semiconductor devices faces challenges in achieving a desired insulating film shape due to scattered light during exposure, and the connectivity between the silicon substrate and insulating film decreases with increasing film thickness, affecting the formation of through electrodes.
Innovation Solution
A semiconductor device is designed with a first substrate of silicon, featuring a first film on the surfaces of hole-shaped portions and a photosensitive second film covering the side surfaces, where the first film can absorb light, have varying thickness, and exhibit different absorption or reflection characteristics, and is made of materials like silicon nitride, silicon oxynitride, or titanium nitride, while the second film is an insulating material such as polyimide or spin-on carbon, enhancing adhesion and patterning resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If exposure and development of lithography technology is used to pattern the insulating film, then the insulating film can be formed, but scattered light during exposure prevents the desired insulating film shape from being obtained
Solution Approach 1:
A light-absorbing film is introduced as an intermediary layer between the silicon substrate and the insulating film. This intermediate layer absorbs scattered light during exposure, preventing it from reaching the photosensitive insulating film and causing unwanted exposure. The light-absorbing film thus mediates between the harmful scattered light and the photosensitive material, enabling precise patterning of the insulating film.
Solution Approach 2:
The scattered light, which is normally a harmful factor causing exposure defects, is converted into a beneficial effect by introducing a light-absorbing film that specifically targets and absorbs this scattered light. The film transforms the problematic scattered light into absorbed energy, preventing it from interfering with the exposure process and enabling accurate pattern formation.
2Reliability
If the thickness of the insulating film is increased, then better insulation is achieved, but connectivity between the silicon substrate and the insulating film decreases
Solution Approach 1:
The light-absorbing film is applied selectively to specific regions where connectivity is critical, such as around through-holes or contact areas. By concentrating the light-absorbing properties in these local regions, the film ensures proper exposure and adhesion only where needed, while allowing the insulating film to maintain its thickness for insulation in other areas. This local application resolves the contradiction between thickness and connectivity.
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 configuration improves the patterning resolution and adhesion of the insulating film, reducing light scattering and maintaining connectivity between the substrate and film, enabling the formation of through electrodes with precise shapes and enhanced electrical connections.
Implementation Method 1
The first film may absorb light having a wavelength sensitive to the second film
Implementation Method 2
The first film may have an adsorption force of a predetermined value or more with respect to the first substrate and the second film
Data Source
AI summary
Provided are a semiconductor device capable of constituting a through electrode having a desired shape, an electronic device, and a method for manufacturing a semiconductor device. The semiconductor device includes: a first substrate including silicon; a first film formed on at least some surfaces of a hole-shaped portion formed in the first substrate; and a photosensitive second film covering at least a part of a side surface of the hole-shaped portion with the first film interposed therebetween.