Semiconductor Specimen Prep Using Selective Adhesive Dielectric Removal
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Solution Overview
Problem
Conventional methods for preparing semiconductor specimens for failure analysis often result in damage to the semiconductor device, especially for advanced technology nodes with thinner dielectric layers, due to manual polishing with chemical etchants, which can expose defects and damage the metal contact layer.
Innovation Solution
A method involving polishing a semiconductor sample to remove the second dielectric layer using an interface layer as a polishing endpoint, followed by forming an adhesive layer with greater adhesion to the first dielectric layer than to the metal contact layer, and then curing and peeling off the adhesive layer to expose the metal contact layer without chemical damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manual polishing with chemical etchants is used to remove the second dielectric layer and wiring layer, then the removal process can be completed, but the semiconductor device may be damaged especially when the dielectric layer is thin
Solution Approach 1:
An adhesive layer is introduced as an intermediary material between the first dielectric layer and the metal contact layer. This adhesive layer serves as a mediator that can be selectively removed to expose the metal contact layer without directly contacting and potentially damaging the semiconductor device structures during the removal process
Solution Approach 2:
The invention replaces the conventional mechanical polishing method with chemical etchants by using adhesive layer formation and peeling. Instead of mechanically removing layers through polishing, the process uses adhesive bonding followed by controlled peeling to achieve layer removal, thereby eliminating mechanical damage and chemical etching damage to the semiconductor device
2Manufacturing precision
If manual polishing is used to expose the metal contact layer, then the second dielectric layer can be removed, but defects may be exposed and the metal contact layer may be damaged
Solution Approach 1:
The adhesive layer acts as a protective intermediary that enables controlled exposure of the metal contact layer. By bonding to the first dielectric layer and being selectively peeled off, it allows precise exposure of the metal contact layer without the harmful effects of mechanical polishing or chemical etching
Solution Approach 2:
The invention extracts and removes only the necessary layers (second dielectric layer and wiring layer) through selective polishing to the interface, then uses adhesive layer peeling to remove part of the first dielectric layer, thereby exposing only the required portion of the metal contact layer without exposing or damaging underlying semiconductor device structures
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 method effectively preserves the metal contact layer and allows controlled removal of the first dielectric layer, preventing damage and defects, making it suitable for advanced technology nodes without chemical reactions.
Implementation Method 1
forming an adhesive layer on the polished semiconductor sample, wherein the adhesion between the adhesive layer and the first dielectric layer is greater than that between the adhesive layer and the metal contact layer
Data Source
AI summary
The present invention discloses a method for preparing a semiconductor sample for failure analysis, which is characterized by using an adhesive layer comprising a non-volatile and non-liquid adhesive material with higher adhesion to the dielectric materials and lower adhesion to the metallic contact materials to selectively remove part of the dielectric materials in a large area with high uniformity, but completely remain the metallic contact materials, and not chemically react with the semiconductor specimens or even damage to the structures of interest to be analyzed, and different adhesive materials can be selected as the adhesive layer to control the adhesion to the dielectric layer, thereby the removed thickness of the dielectric layer can be controlled to provide a semiconductor specimen for failure analysis.