Metal Oxide Interlayer for Low Resistance Semiconductor Contacts
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Solution Overview
Problem
High contact resistance between metal and semiconductor materials in integrated assemblies leads to undesirable operational characteristics such as heating and slow device response, necessitating configurations that reduce this resistance.
Innovation Solution
Maintaining a clean interface between semiconductor and metal materials by avoiding metal silicide and germanide formation, using a thin metal oxide layer, and incorporating selenium or tellurium to improve structural properties and reduce contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If metal is directly contacted with semiconductor material, then electrical contact is achieved, but contact resistance becomes too high leading to heating and slow device response
Solution Approach 1:
A thin layer of metal oxide is introduced as an intermediary between the metal and semiconductor material. This metal oxide layer prevents direct contact that would cause high resistance and harmful heating, while still enabling electrical conduction through the oxide layer itself
Solution Approach 2:
The contact structure uses a composite arrangement of metal, metal oxide, and semiconductor material. This composite structure combines the conductive properties of metal with the protective and conductive properties of metal oxide to achieve low contact resistance without excessive heating
2Reliability
If metal silicide and germanide formation is avoided to maintain clean interface, then contact resistance is reduced, but additional process complexity is introduced
Solution Approach 1:
The metal oxide layer is formed in advance before the metal is deposited. This preliminary formation of the protective oxide layer prevents unwanted silicide and germanide reactions from occurring during subsequent processing, maintaining interface cleanliness without requiring complex post-processing steps
Solution Approach 2:
The metal oxide acts as a protective intermediary that prevents direct chemical reactions between metal and semiconductor materials that would form high-resistance silicides and germanides, while simplifying the overall fabrication process
3Reliability
If selenium or tellurium is incorporated in metal region to improve structural properties, then contact resistance and stability are improved, but material composition complexity increases
Solution Approach 1:
Selenium or tellurium is incorporated locally within specific regions of the metal layer, particularly near the interface with the metal oxide and semiconductor. This localized incorporation provides structural improvement and low contact resistance benefits without requiring complex bulk material composition changes throughout the entire device
Solution Approach 2:
The incorporation of selenium or tellurium modifies the physical and chemical parameters of the metal region, such as lattice structure and bonding characteristics, to improve structural stability and reduce contact resistance while maintaining relatively simple overall material composition
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
The solution achieves low resistance contacts with improved structural properties and stability at high temperatures, enabling efficient semiconductor material integration and reducing operational issues like heating and power demands.
Implementation Method 1
a thin layer of metal oxide may be provided between the metal and the semiconductor material; with the metal oxide precluding formation of metal silicide and/or metal germanide which may otherwise form along the interface
Implementation Method 2
one or both of selenium (Se) and tellurium (Te) may be incorporated within a region of the metal proximate an interface to improve structural properties along the interface
Data Source
AI summary
Some embodiments include an integrated assembly which has a semiconductor material with a surface. A first layer is over and directly against the surface. The first layer includes oxygen and a first metal. The relative amount of oxygen to the first metal is less than or equal to an amount sufficient to form stoichiometric metal oxide throughout the first layer. A second metal is over and directly against the first layer. A second layer is over and directly against the second metal. The second layer includes nitrogen and a third metal. Some embodiments include an integrated assembly which has a semiconductor material with a surface. A metal is adjacent the surface and is spaced from the surface by a distance of less than or equal to about 10 Å. There is no metal germanide or metal silicide between the metal and the surface.