Forming-free aluminum oxide nitride resistive random access memory by atomic layer deposition technique
Abstract/Contents
- Abstract
- The demand for high density non-volatile semiconductor storage has been unrelenting. Even though the industry mitigates the fundamental scaling issue of NAND flash by building vertical devices, other technical challenges arise such as high aspect ratio etching, wafer warpage, limitation of cell current, etc. Several emerging nonvolatile memories (NVM), ferroelectric random access memory (FeRAM), spin-transfer torque random access memory (STT-RAM), phase change random access memory (PCRAM) and resistive random access memory (RRAM), are potential replacement for the current technology (SRAM, DRAM or NAND) or can fill the gap of memory hierarchy as a storage class memory (SCM). Among these emerging NVMs, Al/AlOxNy/Al RRAM has demonstrated low programming currents. The entire RRAM stacks were in situ deposited in a physical vapor deposition (PVD) chamber, which lacks the uniformity and limits the flexibility for large scale manufacturing. The motivation of this thesis includes the theoretical study of AlOxNy RRAM, and the experimental result of 1T1R AlOxNy RRAM by atomic layer deposition (ALD). We have simulated that the substitutional doping of nitrogen (Nsub) in Al2O3 is more favorable comparing to the creation of oxygen vacancy (VO) or interstitial doping of nitrogen (Nint). The defect (intermediate) states from the density of states (DOS) facilitate electron hopping through the device. The device structure with Al/AlOxNy/Al is simulated, the electrostatic potential difference and the transmission characteristic shows lower tunneling barrier and higher transmission for RRAM with VO or Nsub, which support the forming-free characteristic of AlOxNy RRAM. The experimental study of Atomic Layer Deposited (ALD) AlOxNy RRAM stacks start with 1R structure. The device structure, doping concentration, film thickness and interface modulation are optimized. Then, we integrate the optimized Al/AlOxNy/ITO stacks on the NMOS wafer, which provides better electrostatic control. The switching parameters such as form/set/reset voltages, set and reset currents, high and low resistance states are statistically characterized with DC measurements. The retention characteristic is examined under high temperature baking. The endurance is measured under AC pulses. In summary, ALD AlOxNy RRAM, with promising programming characteristics and reliability, has been successfully integrated with CMOS.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2018; ©2018 |
| Publication date | 2018; 2018 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Lien, Yu-Chung |
|---|---|
| Degree supervisor | Wong, S |
| Thesis advisor | Wong, S |
| Thesis advisor | Nishi, Yoshio, 1940- |
| Thesis advisor | Wong, Hon-Sum Philip, 1959- |
| Degree committee member | Nishi, Yoshio, 1940- |
| Degree committee member | Wong, Hon-Sum Philip, 1959- |
| Associated with | Stanford University, Department of Electrical Engineering. |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Yu-Chung Lien. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2018. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2018 by Yu-Chung Lien
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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