Passivation Layer Structure to Limit Antenna Effect on Conductive Pads
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Solution Overview
Problem
As technology nodes decrease, the pitch between conductive pads in semiconductor devices decreases, leading to increased risk of oxidation and antenna effect due to charged particles generated during the deposition of passivation layers, which can damage active components.
Innovation Solution
A dielectric layer with lower conformity is deposited over the conductive pads to act as a barrier, followed by a passivation layer with higher conformity to prevent charged particle accumulation and reduce the antenna effect, using different deposition processes to minimize charge transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HDPCVD process is used to deposit passivation layer with higher conformity, then oxidation protection is improved, but charged particles accumulate and cause antenna effect damaging active components
Solution Approach 1:
The patent divides the single passivation layer into multiple layers: a first passivation layer deposited by HDPCVD for oxidation protection, and a second passivation layer deposited by PECVD to reduce charged particle accumulation. This segmentation allows each layer to perform its specialized function, resolving the contradiction between oxidation protection and antenna effect prevention.
Solution Approach 2:
The first passivation layer acts as an intermediary between the conductive pad and the second passivation layer. It provides the oxidation protection function while the second layer provides the charged particle management function, mediating between the conflicting requirements of conformity and charge accumulation reduction.
2Manufacturing precision
If passivation layer with higher conformity is used, then uniform thickness is improved, but charged particles are directed toward conductive pads increasing antenna effect risk
Solution Approach 1:
The patent segments the passivation structure into two layers with different deposition methods. The first layer (HDPCVD) provides uniform thickness, while the second layer (PECVD) reduces charged particle accumulation. This segmentation resolves the contradiction between manufacturing precision and harmful factor reduction.
Solution Approach 2:
Different regions of the passivation structure have different properties: the first passivation layer has high conformity for uniform protection, while the second passivation layer has lower conformity but better charged particle management. Each layer's local quality is optimized for its specific function.
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
The dielectric layer effectively blocks charged particles, reducing the risk of antenna effect and protecting active devices by providing adequate oxidation protection with controlled thickness variations.
Implementation Method 1
A dielectric layer is over the conductive pad, and a portion of the dielectric layer extends in a direction angled with respect to a top surface of the conductive pad
Implementation Method 2
In order to reduce the risk of oxidation of the conductive pads, passivation layers are deposited over the conductive pads
Implementation Method 3
HDPCVD generates charged particles and these charged particles are directed toward the conductive pads during deposition of the passivation layer
Implementation Method 4
passivation layers are formed using a high density plasma chemical vapor deposition process (HDPCVD)
Data Source
AI summary
A semiconductor device includes a conductive pad over an interconnect structure, wherein the conductive pad is electrically connected to an active device. The semiconductor device includes a dielectric layer over the conductive pad, wherein the dielectric layer has a first conformity, and a portion of the dielectric layer extends in a direction angled with respect to a top surface of the conductive pad. The semiconductor device further includes a passivation layer over the dielectric layer, wherein the passivation layer has a second conformity different from the first conformity, and the passivation layer contacts the dielectric layer.