Silicon Substrate Landing Pad Short-Circuit Prevention
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Solution Overview
Problem
The production of integrated circuits with through silicon vias (TSVs) faces challenges in testing before formation, as opening insulating oxide layers is difficult and costly, and applying metal layers directly on the conductive silicon substrate can lead to short-circuits, preventing pre-formation functionality testing.
Innovation Solution
A method involving a metallic contact structure (landing pad) applied directly to the silicon substrate without an insulating intermediate layer, with an interconnection structure and diode structures introduced into the substrate to block current flow, allowing for testing and preventing short-circuits, and the diode structure is penetrated by the through silicon via during formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulating oxide layer is arranged under the metal layers of the interconnections, then the integrated circuit can be tested before formation of through silicon vias, but the opening of the insulating oxide layer to contact the through silicon via is difficult and costly
Solution Approach 1:
The insulating oxide layer is completely removed (extracted) from the landing pad area to expose the silicon substrate, eliminating the need for difficult opening processes while maintaining testability. The landing pad is applied directly onto the exposed silicon substrate without any insulating intermediate layer.
Solution Approach 2:
The insulating oxide layer is removed in advance (before applying the landing pad) to prepare the surface for direct metal contact. This preliminary removal action enables both direct contact formation and pre-formation testing without subsequent opening steps.
2Ease of manufacture
If metal layers are applied directly onto the conductive silicon substrate, then the production process is simplified, but the metal layers are short-circuited by the silicon substrate preventing functionality testing
Solution Approach 1:
The silicon substrate is selectively modified only in the landing pad contact areas through localized doping to create diode structures, while the rest of the substrate maintains its original properties. This local modification prevents short-circuits at contact points without affecting overall substrate functionality for testing.
Solution Approach 2:
Diode structures are introduced into the silicon substrate at the landing pad contact areas in advance to prevent harmful current flow (short-circuits) between the metal landing pad and the silicon substrate, while allowing functionality testing to proceed.
3Reliability
If an insulating oxide layer is used between the landing pad and silicon substrate, then short-circuits are prevented, but the landing pad cannot be properly contacted with the through silicon via
Solution Approach 1:
The insulating oxide layer is completely removed from the landing pad area to enable direct contact between the through silicon via and the landing pad, eliminating contact formation issues while short-circuits are prevented through diode structures in the silicon substrate.
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
Enables economical and low-risk production of integrated circuits with the ability to test functionality before forming through silicon vias, preventing short-circuits and allowing for effective contact formation.
Implementation Method 1
a diode structure which forms, in particular, at least one diode is introduced into the silicon substrate for blocking a current flow between the contact area of the landing pad and the silicon substrate
Data Source
AI summary
A method is for producing an integrated circuit. In an embodiment, a metallic contact structure, for a through silicon via with a contact area, is applied onto a silicon substrate without an insulating intermediate layer. An interconnection structure, with at least one insulating layer and at least one interconnection layer, is applied onto the silicon substrate. The contact structure is or will be contacted with the interconnection layer or at least one of the possibly plurality of interconnection layers, and a diode structure for blocking a current flow between the contact area of the metallic contact structure and the silicon substrate is introduced into the silicon substrate.