Air Gap Structure Between Bit Lines and Capacitor Contacts
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Solution Overview
Problem
As DRAM memory cell dimensions decrease, increased parasitic capacitance due to capacitive coupling slows down device speeds and negatively impacts overall performance.
Innovation Solution
A semiconductor device with an air gap structure between conductive structures, specifically between bit lines and capacitor contacts, made possible by forming a dielectric structure separated by an air gap, which reduces capacitance and enhances device speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If DRAM memory cell dimensions are reduced to increase packing density, then memory storage capacity is improved, but parasitic capacitance increases and device speed decreases
Solution Approach 1:
An air gap structure is introduced as an intermediary between the bit line and capacitor contact. This air gap acts as a mediator that reduces capacitive coupling between these conductive structures, thereby reducing parasitic capacitance and improving device speed while maintaining the high-density memory cell structure
Solution Approach 2:
The air gap structure utilizes the concept of porous/void spaces between conductive elements. By creating a deliberate void (air gap) between the bit line and capacitor contact, the dielectric constant is reduced compared to solid dielectric materials, which reduces parasitic capacitance and improves signal speed
2Ease of manufacture
If conventional continuous dielectric structures are used between bit lines and capacitor contacts, then manufacturing is simpler, but parasitic capacitance increases and performance deteriorates
Solution Approach 1:
The continuous dielectric structure is segmented into discrete portions with air gaps between them. Specifically, the dielectric structure is divided into first and second portions separated by an air gap, which reduces parasitic capacitance while maintaining manufacturing feasibility through standard deposition and etching processes
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 air gap structure effectively reduces capacitance between bit lines and capacitor contacts, leading to increased speeds and improved overall device performance.
Implementation Method 1
The capacitor contact, the dielectric structure and the first bit line are separated from one another by an air gap structure
Data Source
AI summary
The present application discloses a method for preparing a semiconductor device with an air gap structure between conductive structures. The method includes: forming a first bit line, a second bit line, a first capacitor contact and a second capacitor contact over a semiconductor substrate, wherein the first capacitor contact and the second capacitor contact are disposed between the first bit line and the second bit line; forming a first dielectric layer over a sidewall of the first bit line, a sidewall of the second bit line, a sidewall of the first capacitor contact and a sidewall of the second capacitor contact such that an opening is formed and surrounded by the first dielectric layer; filling the opening with a dielectric structure; and removing the first dielectric layer to form an opening structure surrounding the dielectric structure.