Method for preparing semiconductor device including conductive contact having tapering profile
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The complexity of manufacturing and integration in semiconductor devices leads to performance deficiencies, necessitating improved structures and processes to enhance functionality and reduce contact resistance.
Innovation Solution
A semiconductor device design featuring a conductive contact with a tapering profile in one cross-sectional view and a non-tapering profile in another, along with expanded portions that are entirely covered by a conductive line, reducing contact resistance and preventing crosstalk, is implemented. This design includes forming a conductive layer over a substrate, etching recesses with tapering profiles, and filling them with a conductive material to create the contact and line structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional contact structures are used, then manufacturing is simpler, but contact resistance is high and device performance is limited
Solution Approach 1:
The contact structure is divided into multiple segments: a lower contact portion with first dimensions extending through the first dielectric layer to contact the semiconductor substrate, and an upper contact portion with second dimensions extending through the second dielectric layer. This segmentation allows each portion to be optimized independently for its specific function, reducing overall contact resistance while maintaining manufacturing feasibility.
Solution Approach 2:
The contact structure transitions from a two-dimensional planar contact to a three-dimensional multi-level contact structure by adding vertical stacking of dielectric layers and corresponding contact portions at different elevations. This dimensional change enables reduced contact resistance through improved electrical connection while managing complexity through structured layering.
2Object-affected harmful factors
If contact structures are exposed, then manufacturing is easier, but crosstalk between adjacent lines and contacts increases
Solution Approach 1:
The upper contact portion is nested within the lower contact portion's horizontal footprint, with the upper portion having smaller dimensions than the lower portion. This nesting configuration provides natural shielding and reduces electromagnetic coupling between adjacent contacts, thereby reducing crosstalk while maintaining ease of manufacture through conformal deposition processes.
Solution Approach 2:
Dielectric layers are used as insulating shells surrounding the conductive contact portions. The first dielectric layer surrounds the lower contact portion and the second dielectric layer surrounds the upper contact portion, providing electrical isolation that reduces crosstalk between adjacent contact structures while allowing standard manufacturing processes to be used.
Data Source
AI summary
The present disclosure relates to a method for preparing a semiconductor device including a conductive contact having a tapering profile and a method for preparing the semiconductor device. The method includes forming a conductive layer over a semiconductor substrate, and forming a dielectric layer covering the conductive layer. The method also includes etching the dielectric layer to form an opening exposing the conductive layer, and etching the dielectric layer to form a first recess and a second recess connecting to the opening. A depth of the opening is greater than a depth of the first recess and a depth of the second recess, and the first recess and the second recess have tapering profiles that taper toward the conductive layer. The method further includes forming a conductive contact over the conductive layer. The opening, the first recess and the second recess are filled by the conductive contact.