Interconnect Opening Profile Adjustment to Prevent Bridging
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Solution Overview
Problem
The challenge in semiconductor manufacturing is the formation of tapered interconnect openings due to process variations, leading to a bridging risk and potential short circuits in interconnect structures.
Innovation Solution
An opening-adjustment process is employed to adjust the profiles of interconnect openings by forming a doped film using anisotropic deposition, followed by selective etching to control the critical dimensions and separate adjacent interconnect structures with doped dielectric insulators.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching process is used, then interconnect openings are formed, but the profiles become tapered leading to bridging risk
Solution Approach 1:
The patent applies preliminary action by forming a mandrel structure with predetermined straight sidewalls before the actual interconnect opening formation. This mandrel serves as a template that guides the subsequent etching process, ensuring that the interconnect openings inherit the straight profile from the mandrel rather than developing taper during etching. The mandrel is formed using spin-on-glass material and patterned through photolithography and etching processes that create vertical sidewalls, which then constrain the plasma etching of the interconnect openings to follow the same straight profile.
2Adaptability or versatility
If etching process parameters are varied to improve profile, then manufacturing flexibility increases, but profile control becomes more difficult
Solution Approach 1:
The patent introduces an intermediary mandrel structure that acts as a mediator between the photolithography patterning step and the plasma etching step. This mandrel, formed from spin-on-glass material, serves as a physical template that translates the pattern from the photoresist into a precisely controlled etch profile. The mandrel's straight sidewalls, formed through controlled deposition and pattern transfer, mediate the interaction between the etching process and the desired final profile, ensuring that variations in plasma etching parameters do not compromise the straightness of the interconnect opening profiles.
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 process improves the profiles of interconnect structures, reducing the risk of bridging and short circuits by ensuring adequate spacing between adjacent structures, thereby enhancing semiconductor device reliability.
Implementation Method 1
forming a doped film by an opening-adjustment process, the doped film being disposed on the patterned dielectric layer and extending into the interconnect opening to cover an upper portion of the sidewall surface
Data Source
AI summary
A method for manufacturing a semiconductor device includes: forming a patterned dielectric layer over a substrate, the patterned dielectric layer including an interconnect opening having a sidewall surface and a bottom surface; and forming a doped film by an opening-adjustment process, the doped film being disposed on the patterned dielectric layer and extending into the interconnect opening to cover an upper portion of the sidewall surface, so as to adjust a profile of the interconnect opening.