scholarly journals Microstructures of HfOx Films Prepared via Atomic Layer Deposition Using La(NO3)3·6H2O Oxidants

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7478
Author(s):  
Seon Yong Kim ◽  
Yong Chan Jung ◽  
Sejong Seong ◽  
Taehoon Lee ◽  
In-Sung Park ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Energy ◽  
Atomic Layer Deposition ◽  
Film Growth ◽  
Field Effect Transistors ◽  
Atomic Layer ◽  
Deposition Process ◽  
Oxide Semiconductor ◽  
Layer Deposition ◽  
Wide Range

Hafnium oxide (HfOx) films have a wide range of applications in solid-state devices, including metal–oxide–semiconductor field-effect transistors (MOSFETs). The growth of HfOx films from the metal precursor tetrakis(ethylmethylamino) hafnium with La(NO3)3·6H2O solution (LNS) as an oxidant was investigated. The atomic layer deposition (ALD) conditions were optimized, and the chemical state, surface morphology, and microstructure of the prepared films were characterized. Furthermore, to better understand the effects of LNS on the deposition process, HfOx films deposited using a conventional oxidant (H2O) were also prepared. The ALD process using LNS was observed to be self-limiting, with an ALD temperature window of 200–350 °C and a growth rate of 1.6 Å per cycle, two times faster than that with H2O. HfOx films deposited using the LNS oxidant had smaller crystallites than those deposited using H2O, as well as more suboxides or defects because of the higher number of grain boundaries. In addition, there was a difference in the preferred orientations of the HfOx films deposited using LNS and H2O, and consequently, a difference in surface energy. Finally, a film growth model based on the surface energy difference was proposed to explain the observed growth rate and crystallite size trends.

scholarly journals Atomic Layer Deposition (ALD) of Metal Gates for CMOS

2019 ◽  
Vol 9 (11) ◽  
pp. 2388 ◽  
Author(s):  
Chao Zhao ◽  
Jinjuan Xiang
Keyword(s):  
Atomic Layer Deposition ◽  
Field Effect Transistors ◽  
Material Selection ◽  
Atomic Layer ◽  
Oxide Semiconductor ◽  
Metal Gate ◽  
Gate Stack ◽  
Short Channel ◽  
Metal Gates ◽  
Layer Deposition

The continuous down-scaling of complementary metal oxide semiconductor (CMOS) field effect transistors (FETs) had been suffering two fateful technical issues, one relative to the thinning of gate dielectric and the other to the aggressive shortening of channel in last 20 years. To solve the first issue, the high-κ dielectric and metal gate technology had been induced to replace the conventional gate stack of silicon dioxide layer and poly-silicon. To suppress the short channel effects, device architecture had changed from planar bulk Si device to fully depleted silicon on insulator (FDSOI) and FinFETs, and will transit to gate all-around FETs (GAA-FETs). Different from the planar devices, the FinFETs and GAA-FETs have a 3D channel. The conventional high-κ/metal gate process using sputtering faces conformality difficulty, and all atomic layer deposition (ALD) of gate stack become necessary. This review covers both scientific and technological parts related to the ALD of metal gates including the concept of effect work function, the material selection, the precursors for the deposition, the threshold voltage (Vt) tuning of the metal gate in contact with HfO2/SiO2/Si. The ALD of n-type metal gate will be detailed systematically, based mainly on the authors’ works in last five years, and the all ALD gate stacks will be proposed for the future generations based on the learning.

Atomic Layer Deposition of TiN below 600 K Using N2H4

2018 ◽  
Vol 282 ◽  
pp. 232-237
Author(s):  
Adam Hinckley ◽  
Anthony Muscat
Keyword(s):  
Growth Rate ◽  
Atomic Layer Deposition ◽  
Titanium Nitride ◽  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Detection Limits ◽  
Atomic Layer ◽  
Volatile Species ◽  
X Ray ◽  
Layer Deposition

Atomic layer deposition (ALD) was used to grow titanium nitride (TiN) on SiO2with TiCl4and N2H4. X-ray photoelectron spectroscopy (XPS) and ellipsometry were used to characterize film growth. A hydrogen-terminated Si (Si-H) surface was used as a reference to understand the reaction steps on SPM cleaned SiO2. The growth rate of TiN at 573 K doubled on Si-H compared to SiO2because of the formation of Si-N bonds. When the temperature was raised to 623 K, O transferred from Ti to Si to form Si-N when exposed to N2H4. Oxygen and Ti could be removed at 623 K by TiCl4producing volatile species. The added surface reactions reduce the Cl in the film below detection limits.

Effects of Tris(tert-pentoxy)silanol Purge Time on SiO2 Thin-Film Growth Rate in Rapid Atomic Layer Deposition

2013 ◽  
Vol 2 (10) ◽  
pp. P91-P93 ◽  
Author(s):  
J. R. Kim ◽  
H. Lim ◽  
S. Park ◽  
Y. J. Choi ◽  
S. Suh ◽  
...  
Keyword(s):  
Thin Film ◽  
Growth Rate ◽  
Atomic Layer Deposition ◽  
Film Growth ◽  
Atomic Layer ◽  
Thin Film Growth ◽  
Film Growth Rate ◽  
Sio2 Thin Film ◽  
Layer Deposition

scholarly journals Ellipsometry and XPS comparative studies of thermal and plasma enhanced atomic layer deposited Al2O3-films

2013 ◽  
Vol 4 ◽  
pp. 732-742 ◽  
Author(s):  
Jörg Haeberle ◽  
Karsten Henkel ◽  
Hassan Gargouri ◽  
Franziska Naumann ◽  
Bernd Gruska ◽  
...  
Keyword(s):  
Growth Rate ◽  
Refractive Index ◽  
Atomic Layer Deposition ◽  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Atomic Layer ◽  
Silicon Substrates ◽  
Initial State ◽  
Elemental Ratios ◽  
Layer Deposition

We report on results on the preparation of thin (<100 nm) aluminum oxide (Al2O3) films on silicon substrates using thermal atomic layer deposition (T-ALD) and plasma enhanced atomic layer deposition (PE-ALD) in the SENTECH SI ALD LL system. The T-ALD Al2O3 layers were deposited at 200 °C, for the PE-ALD films we varied the substrate temperature range between room temperature (rt) and 200 °C. We show data from spectroscopic ellipsometry (thickness, refractive index, growth rate) over 4” wafers and correlate them to X-ray photoelectron spectroscopy (XPS) results. The 200 °C T-ALD and PE-ALD processes yield films with similar refractive indices and with oxygen to aluminum elemental ratios very close to the stoichiometric value of 1.5. However, in both also fragments of the precursor are integrated into the film. The PE-ALD films show an increased growth rate and lower carbon contaminations. Reducing the deposition temperature down to rt leads to a higher content of carbon and CH-species. We also find a decrease of the refractive index and of the oxygen to aluminum elemental ratio as well as an increase of the growth rate whereas the homogeneity of the film growth is not influenced significantly. Initial state energy shifts in all PE-ALD samples are observed which we attribute to a net negative charge within the films.

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