Bit Line Contact Structure for Dense DRAM With Lower Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor memory devices is to increase memory cell density while improving the efficiency and reliability of the fabricating processes, particularly in DRAMs with recessed gate structures, where the complexity of bit line connections affects the structural reliability and leakage current.
Innovation Solution
A semiconductor device with a bit line contact comprising a composite conductive layer, including a first conductive layer and a first oxidized interface layer, where the bottommost surface of the oxidized interface layer is lower than the top surface of the insulating layer, is formed to enhance the electrical connection and structural reliability of bit lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If memory cell density is increased to meet high integration requirements, then storage capacity is improved, but fabrication process complexity and difficulty increase
Solution Approach 1:
The bit line contact is segmented into multiple functional layers: a first conductive layer for electrical connection, a first oxidized interface layer for structural stability, and a second conductive layer for additional conductivity. This segmentation allows each layer to be optimized independently, enabling high density while managing fabrication complexity through modular construction
Solution Approach 2:
Different regions of the bit line contact are given different properties through the layered structure. The first conductive layer provides electrical connection quality, the oxidized interface layer provides structural stability at the interface, and the second conductive layer enhances overall conductivity. This local differentiation of material properties enables high density integration without compromising fabrication reliability
2Reliability
If bit line contact structural reliability is improved through composite layers, then device performance is enhanced, but fabrication process complexity increases
Solution Approach 1:
The bit line contact employs a composite structure combining different conductive materials and oxidized interface layers. The first conductive layer (e.g., tungsten) provides mechanical strength and electrical connection, the first oxidized interface layer (e.g., tungsten oxide) provides structural stability and interface quality, and the second conductive layer (e.g., copper or aluminum) enhances conductivity. This composite approach improves reliability while the standardized fabrication process manages complexity
3Reliability
If oxidized interface layer is formed with bottommost surface lower than insulating layer top surface, then electrical connection and structural reliability are improved, but manufacturing precision requirements increase
Solution Approach 1:
The first oxidized interface layer is formed preliminarily before the second conductive layer, establishing a stable foundation with its bottommost surface positioned below the insulating layer top surface. This preliminary oxidation creates a robust interface structure that facilitates subsequent layer formation and reduces precision requirements for later steps, as the critical interface is already established
Solution Approach 2:
The first oxidized interface layer acts as an intermediary between the first conductive layer and the insulating layer, with its bottommost surface positioned below the insulating layer top surface. This intermediary structure provides a transition zone that improves electrical connection and structural reliability while accommodating manufacturing tolerances through its intermediate positioning
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 configuration improves the structural reliability and performance of semiconductor devices by reducing leakage current and enhancing the density of memory cells, simplifying the fabricating process and improving device functionality.
Implementation Method 1
a bit line contact is formed between the bit lines and the substrate, to electrically connect the bit lines, wherein the bit line contact includes a first conductive layer and a first oxidized interface layer
Data Source
AI summary
The present disclosure provides a semiconductor device and a method of fabricating the same, the semiconductor device includes a substrate, an insulating layer, a plurality of bit lines, and a bit line contact. The insulating layer is disposed on the substrate, the bit lines are disposed on the insulating layer, and the bit line contact is disposed between the bit lines and the substrate, to electrically connect the bit lines, wherein the bit line contact comprises a first conductive layer and a first oxidized interface layer, and a bottommost surface of the first oxidized interface layer is lower than a top surface of the insulating layer. Through these arrangements, the semiconductor device includes the bit line contact having a composite semiconductor layer, which is allowable to improve the structural reliability of the bit lines and the bit line contacts, thereby achieve better performance.