Thin-Film Passive Layout With Bottom Contact Pick-Up
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Solution Overview
Problem
Existing methods for integrating thin film based passive components in semiconductor devices face challenges such as punch-through during reactive-ion etching and contamination risks due to exposure of metallic elements, particularly in the CMOS back-end-of-line process, which complicates the integration and handling of these components.
Innovation Solution
The integration of a nitride block insulator over interconnect levels in semiconductor devices, with contact plugs that line openings to prevent out-diffusion of conductive material and allow for the placement of thin film passive components without exposing metallic elements, enabling uniform contact pick-up and avoiding contamination risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional top side via pick-up configuration is used to contact TFR, then integration into existing process flow is achieved, but punch-through occurs during reactive-ion etch process
Solution Approach 1:
The patent inverts the conventional contact configuration by moving the contact point from the top side to the bottom side of the thin film resistor. This bottom pick-up configuration allows the contact to be established before the reactive-ion etch process, eliminating the punch-through issue that occurs when contacting from the top side during etching.
Solution Approach 2:
The contact point is formed in advance before the reactive-ion etch process occurs. By establishing the bottom contact configuration prior to etching, the thin film resistor is protected from punch-through damage that would occur if top-side contact points were exposed during the etch process.
2Ease of operation
If metallic elements are exposed during thin film integration, then contact points can be established, but contamination risks increase
Solution Approach 1:
By inverting the contact configuration to bottom pick-up, the metallic contact points are positioned on the bottom side of the thin film resistor where they remain protected from exposure during subsequent processing steps. This eliminates the contamination risk associated with exposed metallic elements on the top side.
Solution Approach 2:
The thin film structure itself acts as an intermediary protective layer that covers and protects the metallic contact points on the bottom side. This intermediary layer prevents direct exposure of the metallic elements to the environment and processing chemicals, thereby reducing contamination risks.
3Manufacturing precision
If buffer layer or liner is added to protect thin film, then integration complexity increases, but manufacturing precision is improved
Solution Approach 1:
The bottom pick-up configuration eliminates the need for additional buffer layers or liners that would be required in top-side contact configurations. By contacting from the bottom, the thin film resistor can be directly integrated into the existing process flow without adding protective intermediate layers, thus reducing overall device complexity.
Data Source
AI summary
A device may include a substrate, and an interlevel dielectric arranged over the substrate. The interlevel dielectric may include a first interlevel dielectric layer in an interconnect level i, the first interlevel dielectric layer having a first interconnect and a second interconnect therein. A nitride block insulator may be arranged over the first interlevel dielectric layer and over the first interconnect and the second interconnect. An opening may be arranged in the nitride block insulator, the opening extending through the nitride block insulator to expose a surface of the first interconnect in the first interlevel dielectric layer. A contact plug may be arranged in the opening of the nitride block insulator. The contact plug at least lines the opening and prevents out-diffusion of conductive material from the first interconnect. A thin film of a passive component may be arranged over the nitride block insulator and over the contact plug.