Semiconductor Ridge Sidewall Passivation for Insulation and Heat Conduction
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Solution Overview
Problem
Existing techniques for passivating sidewalls of semiconductor wafers with ridges are inefficient in insulating and cooling, leading to current and optical leaks, and complicate metallization due to non-uniform dielectric deposition, with strict alignment requirements and inadequate heat conduction.
Innovation Solution
A method involving the deposition of a first dielectric layer, etching to create tapered portions, followed by a second dielectric layer and photo-sensitive material processing to achieve optimal passivation, allowing for efficient insulation and heat conduction while easing alignment and metallization challenges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a thick layer of dielectric material is deposited to insulate sidewalls, then insulation performance is improved, but heat conduction capability deteriorates
Solution Approach 1:
The patent divides the dielectric material into two distinct layers: a first dielectric layer (e.g., silicon nitride) providing electrical insulation, and a second dielectric layer (e.g., silicon dioxide) providing thermal conduction. This segmentation allows each layer to optimize its specific function without compromising the other, resolving the contradiction between insulation performance and heat conduction capability.
Solution Approach 2:
The patent employs a composite structure combining two different dielectric materials with complementary properties. The first dielectric layer offers high electrical insulation, while the second dielectric layer provides superior thermal conduction. This composite approach enables simultaneous achievement of both insulation and cooling requirements that cannot be met by a single material.
2Object-affected harmful factors
If existing passivation techniques are used, then sidewalls are protected from oxidation, but current leaks and optical leaks occur due to poor insulation
Solution Approach 1:
The patent uses a composite dielectric structure where the first dielectric layer (such as silicon nitride) provides superior electrical insulation properties compared to conventional single-layer approaches. This enhanced insulation prevents current leaks and optical leaks while maintaining protection from oxidation, directly resolving the contradiction between environmental protection and electrical insulation performance.
3Reliability
If dielectric material is deposited over ridges, then sidewalls are passivated, but sharp edges and non-uniform edges are formed complicating metallization
Solution Approach 1:
The patent performs preliminary etching of the first dielectric layer to create tapered portions at the sidewalls before depositing the second dielectric layer. This preliminary action prevents the formation of sharp edges and non-uniformities that would complicate subsequent metallization processes, while still maintaining effective passivation of the sidewalls.
Solution Approach 2:
By dividing the passivation into two sequential steps using two different dielectric layers, the patent enables intermediate processing (etching tapered portions) that simplifies the final structure for metallization. This segmented approach allows optimization of each layer's properties and facilitates easier manufacturing compared to single-layer deposition.
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 method effectively minimizes current and optical leaks, enhances heat conduction, and simplifies metallization by providing a robust and tolerant passivation solution for semiconductor devices, improving operational characteristics and fabrication yields.
Implementation Method 1
depositing a first layer of a first dielectric material on a pattern surface of the patterned semiconductor wafer
Implementation Method 2
etching a portion of the first layer to obtain tapered portions of the first dielectric material along at least one sidewall of the at least one ridge
Implementation Method 3
depositing a second layer of a second dielectric material on the tapered portions and the patterned semiconductor wafer
Implementation Method 4
exposing the photo-sensitive material to a light source, to remove the at least one portion of the photo-sensitive material
Implementation Method 5
The tapered portions of the first dielectric material are obtained along at least one sidewall of the at least one ridge... properly conducting the heat away from the semiconductor device
Data Source
AI summary
A method for passivating sidewalls of patterned semiconductor wafer including ridge(s). The method includes: depositing first layer of first dielectric material on pattern surface of said wafer; etching portion of first layer to obtain tapered portions of first dielectric material along sidewall(s) of ridge(s); depositing second layer of second dielectric material on tapered portions and said wafer; depositing photo-sensitive material on second layer; aligning mask with photo-sensitive material, wherein portion(s) of photo-sensitive material corresponding to top surface of ridge(s) is/are unmasked, and remaining portion is masked; applying developing solution and exposing photo-sensitive material to remove portion(s) of photo-sensitive material; etching portion(s) of second layer that is/are deposited on top surface of ridge(s); and removing photo-sensitive material.