Through-Silicon Via Structure Using Double-Sided Plasma Etching
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Solution Overview
Problem
Conventional through silicon via manufacturing processes face inefficiencies due to low etching rates and material waste, particularly in the thinning of silicon wafers and the deep etching required for three-dimensional integrated circuit packaging, which affects production efficiency and increases costs.
Innovation Solution
The method involves hydrogen ion implantation to lift off silicon wafers, followed by double-sided plasma etching to form through silicon vias, and subsequent deposition of insulating and conductive layers, eliminating the need for chemical-mechanical polishing and optimizing the etching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If mechanical grinding is used to thin silicon wafers, then the overall thickness of the package is reduced, but a considerable thickness of silicon material is removed without being recycled, resulting in material waste
Solution Approach 1:
The patent replaces mechanical grinding with chemical etching processes (wet etching and vapor HF etching) to remove silicon material. This substitution allows for more precise control of material removal and reduces waste by enabling selective etching of only the necessary portions to achieve the desired thickness and through-via formation.
Solution Approach 2:
The patent changes the physical and chemical parameters of the silicon wafer processing by using controlled chemical reactions instead of mechanical forces. By adjusting etching parameters such as chemical concentration, temperature, and exposure time, the desired thickness reduction is achieved with minimal material waste.
2Manufacturing precision
If the silicon wafer is etched on one side only, then the through silicon via is formed, but the etching rate is rather low, affecting production efficiency
Solution Approach 1:
The patent divides the etching process into two separate sides, allowing simultaneous or sequential etching from both the front and back of the silicon wafer. This segmentation of the etching operation effectively doubles the material removal rate while maintaining precise control over through-via formation, thereby improving production efficiency without sacrificing manufacturing precision.
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 enhances etching rates, reduces material waste, and simplifies the manufacturing process, leading to higher production efficiency and lower costs while maintaining high performance in three-dimensional integrated circuit packaging.
Implementation Method 1
lifting off a silicon wafer by implanting hydrogen ions into the silicon wafer to obtain a substrate for making a through silicon via
Implementation Method 2
performing double-sided plasma etching on the substrate to form a through silicon via penetrating the substrate
Implementation Method 3
electroplating a conductive metal material into the through silicon via
Data Source
AI summary
The present disclosure belongs to the technical field of integrated circuit packaging, and specifically relates to a through silicon via structure for three-dimensional integrated circuit packaging and a manufacturing method thereof. The method of the present disclosure includes the following steps: lifting off a silicon wafer by implanting hydrogen ions into the silicon wafer to obtain a substrate for making a through silicon via; performing double-sided plasma etching on the substrate to form a through silicon via penetrating the substrate; depositing an insulating medium, a copper diffusion barrier layer, and a seed layer; and removing parts of the copper diffusion barrier layer and the seed layer by photolithography and etching processes, leaving only parts of the copper diffusion barrier layer and the seed layer on a sidewall of the through silicon via; forming a sacrificial layer on the upper and lower surfaces of the resulting structure, completely filling in the through silicon via with conductive metal material, and then removing the sacrificial layer, upper and lower surfaces of the conductive metal material respectively protruding from upper and lower surfaces of the insulating medium; and forming a contact pad on a surface of the conductive metal material. The present disclosure can effectively improve production efficiency and lower the cost.