Through-Hole Electrode Structure for Uniform Chip Stacking
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Solution Overview
Problem
Existing semiconductor devices face challenges in achieving uniformity in the depth and height of through-hole electrodes and conductive pads, which affects the ease of manufacturing and stacking of semiconductor chips.
Innovation Solution
The implementation of an etch stop layer and conductive pad layer during the dry etching process ensures uniform depth and height of through-hole electrodes and conductive pads by controlling the etching process, resulting in structures with varying slopes and protrusions that facilitate easy stacking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If through-hole electrodes are formed with different widths to enhance HBM device performance, then device performance is improved, but uniformity in depth and height of through-hole electrodes and conductive pads deteriorates
Solution Approach 1:
An etch stop layer is formed prior to forming the through-hole electrodes. This etch stop layer serves as a predetermined reference that ensures uniform etching depth across through-hole electrodes of different widths, thereby maintaining manufacturing precision while allowing performance enhancement through varied electrode widths.
Solution Approach 2:
The patent utilizes the etch stop layer to control the etching process parameter (etching depth) uniformly across different electrode structures. By changing the reference parameter from electrode width to etch stop layer position, uniformity in depth and height is maintained despite variations in electrode widths.
2Ease of operation
If through-hole electrodes have non-flat upper surfaces with varying slopes, then ease of stacking is improved, but manufacturing complexity increases
Solution Approach 1:
The etch stop layer is formed in advance as a reference structure. During etching, this pre-formed layer automatically creates the desired non-flat upper surfaces with varying slopes on the through-hole electrodes, facilitating easy stacking. The complexity is reduced because the slope formation is a byproduct of the etching process against the etch stop layer reference, rather than requiring additional shaping steps.
3Ease of manufacture
If conventional etching processes are used without etch stop layer, then manufacturing process is simpler, but uniformity in depth and height of structures cannot be achieved
Solution Approach 1:
The etch stop layer acts as an intermediary element between the etching process and the through-hole electrodes. It mediates the etching process to ensure uniform depth and height across structures of different widths, achieving manufacturing precision without significantly complicating the overall manufacturing process.
Solution Approach 2:
By introducing the etch stop layer, the reference parameter for controlling etching uniformity changes from the electrode geometry itself to the position and thickness of the etch stop layer. This parameter change enables uniformity in depth and height to be achieved through a relatively simple process modification.
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 allows for the fabrication of semiconductor devices with uniformly heighted through-hole electrodes and conductive pads, enhancing manufacturing efficiency and enabling easy stacking of semiconductor chips.
Implementation Method 1
The implementation of an etch stop layer and conductive pad layer during the dry etching process ensures uniform depth and height of through-hole electrodes and conductive pads by controlling the etching process
Data Source
AI summary
A semiconductor device includes a substrate, an etch stop layer on the substrate, a through-hole electrode extending through the substrate and the etch stop layer in a vertical direction substantially perpendicular to an upper surface of the substrate, and a conductive pad. The etch stop layer includes a first surface adjacent to the substrate and a second surface opposite the first surface. The through-hole electrode includes a protrusion portion that protrudes from the second surface of the etch stop layer. The conductive pad covers the protrusion portion of the through-hole electrode. The protrusion portion of the through-hole electrode is not flat.