Dummy Pad Seal Ring Dissipates Static Charge in Semiconductor Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Dummy pads in semiconductor devices are prone to dielectric breakdown due to static electricity and plasma generated during manufacturing processes, leading to potential damage and defects, especially as the thickness of insulation films decreases, and existing solutions like connecting dummy pads to internal circuits through resistors increase electrical noise and capacitance.
Innovation Solution
A semiconductor device design where dummy pads are not electrically connected to the internal circuit but are connected to a seal ring that surrounds the internal circuit and is electrically connected to the semiconductor substrate, allowing electrical charges to dissipate into the substrate, thereby preventing dielectric breakdown without introducing additional protection circuits or noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If dummy pads are not electrically connected to the internal circuit, then electrical noise and capacitance are avoided, but dielectric breakdown occurs due to static electricity and plasma during manufacturing processes
Solution Approach 1:
A seal ring is introduced as an intermediary component between the dummy pad and the internal circuit. The seal ring provides a discharge path for static electricity and plasma to the substrate while being electrically isolated from the internal circuit by an insulation film, thus preventing both dielectric breakdown and electrical noise transmission
Solution Approach 2:
The electrical path is segmented into two separate paths: one for static electricity discharge (through the seal ring to substrate) and one for signal transmission (internal circuit). This segmentation allows the dummy pad to be connected to both the seal ring and internal circuit without causing electrical noise or capacitance issues
2Reliability
If dummy pads are electrically connected to the internal circuit through a resistor, then static electricity is attenuated and dielectric breakdown is prevented, but electrical noise and capacitance increase
Solution Approach 1:
The seal ring acts as a mediator that provides static electricity discharge path without requiring a resistor. By connecting the dummy pad to the seal ring which is connected to the substrate, static electricity is dissipated without introducing the electrical noise and capacitance problems associated with resistor-based protection circuits
3Productivity
If the thickness of insulation film is reduced for circuit refinement, then integration density increases, but dielectric breakdown becomes more significant due to lower breakdown voltage
Solution Approach 1:
The static electricity discharge function is extracted from the insulation film system. Instead of relying on the insulation film to prevent breakdown, a separate seal ring structure is provided that actively dissipates static electricity before it can cause breakdown, allowing the insulation film to be made thinner for higher integration density
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 design effectively prevents dielectric breakdown during manufacturing processes by dissipating electrical charges into the substrate, minimizing the risk of damage and noise interference with the internal circuit, while maintaining layout uniformity and avoiding increased manufacturing costs.
Implementation Method 1
a seal ring which surrounds the internal circuit and is electrically connected to the semiconductor substrate... electrically connected to the seal ring... allowing electrical charges to dissipate into the substrate
Data Source
AI summary
A semiconductor device that prevents a build-up of electrostatic charge in a dummy pad is provided. The semiconductor device may contain an internal circuit formed on a semiconductor substrate and the dummy pad which is not electrically connected to the internal circuit. The semiconductor device may further include a seal ring that surrounds the internal circuit and the dummy pad, where the seal ring is electrically connected to the semiconductor substrate and includes a pattern in a first metal layer, a contact between the pattern in the first metal layer and the semiconductor substrate, patterns in upper metal layers stacked above the pattern in the first metal layer, and multiple electrical contacts between the patterns in the first metal layer and the upper metal layers, in which the dummy pad is electrically connected to the seal ring.