Doped HfZrO Ferroelectric Layer Deposition for Low Wakeup Memory
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Solution Overview
Problem
There is a need to improve the performance of ferroelectric memories and transistors with multiple threshold voltages in modern integrated circuits, specifically in the use of ferroelectric layers as gate dielectrics for MISFETs, where existing technologies have limitations in device performance.
Innovation Solution
A method involving multiple deposition cycles with hafnium and zirconium precursors, oxygen reactants, and dopant pulses is used to form a doped hafnium zirconium oxide layer on a substrate, where the dopant precursor pulses can be executed after either the hafnium or zirconium precursor pulses without an intervening oxygen reactant pulse, and the layer is further processed with annealing and top electrode formation in a system with multiple processing chambers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional deposition methods are used to form ferroelectric layers, then the basic memory function is achieved, but the device performance is insufficient with high wakeup cycles and low endurance
Solution Approach 1:
The patent applies parameter changes by modifying the deposition process parameters including using specific precursor sequences (hafnium, zirconium, oxygen, dopant), controlling deposition temperature ranges, and adjusting oxygen partial pressures to form HfZrO4 layers with optimized ferroelectric properties that achieve low wakeup cycles and high endurance
Solution Approach 2:
The patent uses composite materials by creating doped HfZrO4 layers combining hafnium oxide and zirconium oxide in specific ratios, with additional dopant elements incorporated during deposition to enhance ferroelectric performance, resulting in materials with improved reliability and endurance characteristics
2Reliability
If ferroelectric layers are formed without dopants, then the deposition process is simpler, but the remnant polarization is insufficient for high-performance memory applications
Solution Approach 1:
The patent applies preliminary action by incorporating dopant elements during the deposition process itself rather than requiring subsequent separate doping steps, allowing the dopant to be integrated into the HfZrO4 layer structure during formation, which simplifies the overall process while achieving high remnant polarization
Solution Approach 2:
The patent merges multiple functions by combining layer formation and dopant incorporation into a single deposition process, where the dopant precursor is introduced alongside hafnium and zirconium precursors, eliminating the need for separate doping steps and reducing process complexity
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 approach results in improved device performance with low wakeup cycles, good endurance, and high remnant polarization, enabling the formation of doped hafnium zirconium oxide layers suitable for ferroelectric random access memory and field effect transistors.
Implementation Method 1
A method is provided herein of processing a substrate. The method comprises providing the substrate to a processing chamber. The method further comprises executing a plurality of deposition cycles. A deposition cycle comprises a hafnium precursor pulse, a zirconium precursor pulse, an oxygen reactant pulse, and a dopant pulse.
Implementation Method 2
The oxygen reactant pulse comprises exposing the substrate to an oxygen reactant
Implementation Method 3
the step of forming a top electrode on the hafnium zirconium oxide layer is preceded by annealing the hafnium zirconium oxide layer
Data Source
AI summary
Methods and related systems of processing a substrate. Described methods comprise executing a plurality of deposition cycles to form a doped hafnium zirconium oxide layer on the substrate.