Post-deposition Annealing Temperature Research Articles

Tuning of interface quality of Al/CeO2/Si device by post-annealing of sol-gel grown high-k CeO2 layers

A comprehensive study has been done on the influence of post-deposition annealing temperature on high-k cerium oxide (CeO2) layer grown on n-type silicon (Si) substrate and its resultant interface states have been studied for Al/CeO2/Si metal-oxide-semiconductor (MOS) devices. The high-k CeO2 thin films were deposited by spin-coating and sintered at different annealing temperatures (Ta) in the range of 400–900 °C. The parameters such as fixed charge density (Qeff), dielectric constant (k) of the layers, flat-band voltage (VFB), interface defect density (Dit), etc., of the MOS device were evaluated from CV and I-V measurements. A minimum value of flat band shift (~0.05 V) with lower Qeff (−4.81 × 1011 C/cm2) have been achieved for the Ta of 600 °C. The k and Dit were evaluated to be 22 and 1.29 × 1012 cm−2, respectively at the Ta of 600 °C. In addition, the CV measurements showed a very small hysteresis and very low frequency dispersion for the Ta of 600 °C sample. Energy distribution of defect states was evaluated and it was maximum towards the bottom of the conduction band. This shows that the 600 °C is the optimum annealing temperature, which results in high quality interface, and the electron affinity of the corresponding CeO2 layers was found to be 3.29 eV as evaluated from ultraviolet photoelectron spectroscopy (UPS). Further, a maximum value of minority carrier lifetime (147 μs) has been achieved for the samples annealed at Ta of 400 °C, indicating that the post-annealing temperature plays a significant role on the properties of CeO2 films deposited by sol-gel process. Thus, the present study demonstrates the possibility of sol-gel grown high k-CeO2 layers suitable for MOS like devices.

Hindrances and solutions on the path towards adjoined barium titanate–hydroxyapatite ceramics with uncompromised piezoelectric and biological responses

The synergistic piezoelectric and osteoconductive properties of barium titanate (BT) and hydroxyapatite (HA) could stir the development of a new generation of synthetic bone graft substitutes, with capability for rapid and safe osseointegration. The research focused on two concurrent approaches for coupling the BT and HA materials: (i) conventional sintering of BT-HA powder mixtures; and (ii) functionalization of pre-sintered BT with HA coatings using magnetron sputtering (MS). Irrespective of the BT/HA ratios ranging from 95/5 to 80/20 wt%, nanocrystalline or highly-crystallized nature of the powders, sub-micron- or micron-sized particle dimensions, and sintering temperature, it was observed that the BT-HA reactivity cannot be prevented above 800 °C. At higher temperatures in the range of 1000–1300 °C, HA undergoes decomposition and extensively reacts with BT, leading to the formation of several secondary phases such as CaTiO3, Ba2Ca(PO4)2, BaCa6(PO4)4O, BaCa(PO3)4, and β-Ca2P2O7. As a consequence, the cytocompatibility assessed in fibroblast and osteoblast cell cultures, as well as the piezoelectric response, were significantly altered.Applying HA coatings by MS to the sintered BT ceramics successfully preserved their piezoelectric properties, while also providing an unaltered cytocompatible and osteogenic-prone surface. The HA coatings were fully crystallized at post-deposition annealing temperatures of 550 and 700 °C, achieving crystalline qualities comparable to HA powders sintered at 1100 and 1200 °C, respectively. No reactivity events between BT and HA were observed. Partial reactivity was only noticeable upon annealing at 1000 °C. Therefore, it is suggested that the HA coating of BT is effective in seamlessly coupling the piezoelectric and osteogenic properties of the two constituents without compromise.

Post-annealing effect of low temperature atomic layer deposited Al2O3 on the top gate IGZO TFT

Electronical properties of top gate amorphous InGaZnO4 thin film transistors (TFTs) could be controlled by post-annealing treatment, which has a great impact on the Al2O3 insulator. To investigate the effect of post-annealing on Al2O3, Al/Al2O3/p-Si MOS capacitoras with Al2O3 films treated under various post-deposition annealing (PDA) temperature were employed to analysis the change of electrical properties, surface morphology, and chemical components by electrical voltage scanning, atomic force microscope (AFM), and x-ray photoelectron spectroscopy (XPS) technologies. After PDA treatment, the top gate TFTs had a mobility about 7 cm2 V−1 s−1 and the minimum subthreshold swing (SS) about 0.11 V/dec, and the threshold voltage (V th) shifted from positive direction to negative direction as the post-annealing temperature increased. Electrical properties of MOS capacitors revealed the existence of positive fixed charges and the variation of trap state density with increasing PDA temperature, and further explained the change of negative bias stress (NBS) stability in TFT. AFM results clarified the increased leakage current, degraded SS, and NBS stability in MOS capacitors and TFTs, respectively. XPS results not only illuminated the origin of fixed charges and the trap density variation with PDA temperatures of Al2O3 films, but also showed the O and H diffusion from Al2O3 into IGZO during post-annealing process, which led to the deviation of V th, the change of current density, and the negative V th shift after positive bias stress in TFTs.

Impact of Nitrogen Concentration and Post‐Deposition Annealing on Electrical Properties of AlON/Etched N‐GaN MOS Capacitors

AbstractElectrical and material properties of plasma‐enhanced atomic layer deposited (PE‐ALD) AlON on dry‐etched n‐type GaN substrates are investigated for nitrogen concentration ranging from 1.5% to 7.1%. Firstly, an increase in flat‐band voltage (VFB) and its hysteresis with increasing nitrogen concentration is reported. The increase in VFB is associated with the nitrogen content whereas the increase in hysteresis to the presence of impurities (hydroxyl groups and carbon‐related impurities). Alongside the nitrogen concentration, the impact of different post‐deposition annealing (PDA) temperatures is studied (400–800 °C). Stable AlON layers and interfaces with etched GaN substrates are reported with slight gallium oxide growth or gallium diffusion towards the dielectric layer. Finally, with increasing PDA temperature, an increase in VFB and a significant reduction of both VFB hysteresis and interface state density (Dit) are observed, notably at the measuring temperature of 150 °C. These results present a promising pathway toward more reliable and stable normally‐OFF GaN‐based MOS‐channel high electron mobility transistors (MOSc‐HEMTs).

Exploring the impact of different annealing conditions on physical properties of CdSeTe thin films for solar cell absorber layer applications

The perovskite and Silicon based single junction solar cells certainly showed higher efficiency but the perovskite solar cells are highly degradable and unstable in environment whereas conventional Silicon solar cells are relatively costly. The CdTe absorber based thin film solar cells have attained efficiency of greater than 22% where doping of Selenium into the CdTe absorber layer seems to improve the photovoltaic performance. The CdCl2 treatment is proven to be critical process which induces the grain growth and recrystallization in CdSeTe films. Thus herein, air and CdCl2 annealing is performed over thermally evaporated CdSeTe thin films to seek out their applicability as an effective absorber for Cd-based thin film photovoltaics. The XRD diffractograms exposed the appearance of cubic phase with (111) preferred orientation where crystallite size is increased with annealing temperature. The optical absorbance is found to be altered with temperature of annealing and Tauc’s plots exhibited that bandgap is found to be changed in the range of 1.40–1.52 eV with increasing annealing temperature. Electrical analysis divulges Ohmic character of films where electrical resistivity and conductivity are affected by nature and temperature of post-deposition annealing. The EDS patterns confirmed the deposition of CdSeTe thin films and post deposition CdCl2 activation treatment. The FESEM images demonstrated alteration in surface morphology by grain growth where the grain size of CdSeTe films is increased from 70 nm to 235 nm with CdCl2 annealing temperature. The findings confirm that annealed CdSeTe thin films showed demanding behavior for solar cell devices as prominent light harvesting absorber layers.

Optical Characterization of Semiconducting Thin Films Using UV-VIS-NIR Spectroscopy: A Review

The review article focuses on the growth of thin film and its characterization by UV-Vis-NIR spectroscopy. For UV-Vis-NIR spectroscopy of thin films, they are usually deposited on translucent quartz glass surfaces. The article reports the extraction of various thin film optical parameters viz., absorption coefficient (α), Urbach energy (Eu), optical band gap (Eg), refractive index (n), extinction coefficient (k), dielectric constants, dissipation factor (tanδ) and optical conductivity (σoptical) by using optical spectra (absorption(A)/transmittance (T)/reflectance (R)). Furthermore, the effect of thin film substrate temperature (Ts) and/or thickness (d) and/or post-deposition annealing temperature (Ta) on various optical parameters is discussed in detail.

Effect of high temperature annealing on cryogenic transport properties of silicon MOSFETs with a thin SiO2/HfO2 stacked dielectric

Quantum computing is expected to break the computing power bottleneck with the help of quantum superposition and quantum entanglement. In order to fabricate fault-tolerant quantum computers for encoding quantum information, it is important to improve the cryogenic mobility of silicon-based metal oxide semiconductor field effect transistors (MOSFETs) with a thin gate dielectric layer as much as possible. Based on a thin SiO2/HfO2 stacked dielectric, we investigate the effect of post-deposition annealing (PDA) temperature on the MOSFET cryogenic transport properties. The results show that silicon atoms will diffuse into the HfO2 to form silicates during PDA, leading to the HfO2 dielectric constant decrease. As the PDA temperature increases, the proportion of monoclinic hafnium oxide decreases and the tetragonal phase increases gradually. The oxygen vacancy content increases gradually, resulting in fixed charge density increases and the mobility decreases. The contribution of the forming gas annealing (FGA) to the mobility enhancement is clarified and the HfO2 recrystallization process is revealed from the perspective of long-time annealing. Finally, the mobility peak of silicon MOSFETs with thin SiO2/HfO2 dielectrics is enhanced to 1387 cm2(V·s)−1 at 1.6 K, which provides a technical pathway for the development of silicon-based quantum computation.

Exploring hafnium oxide's potential for passivating contacts for silicon solar cells

We investigate the potential of ultra-thin HfO2 films grown by atomic layer deposition for passivating contacts to silicon focusing on variations in film thickness and post-deposition annealing temperature. A peak in passivation quality – as assessed by carrier lifetime measurements – is reported for 2.2 nm thick films annealed at 475 °C, for which a surface recombination velocity <1 cm/s is determined. For films <2.2 nm thick, there is a marked decrease in passivation quality. X-ray diffraction highlights a change from crystallised monoclinic to amorphous HfO2 as film thickness decreases from 12 nm to 2.2 nm. Kelvin probe results indicate that as-deposited 2.2–12 nm films have similar effective work functions, although the work function of 1 nm films is considerably lower. Upon post-deposition annealing in vacuum, all films exhibit a reduction in effective work function at temperatures coincident with the onset of passivation in air-annealed samples. An initial investigation into the contact resistivity in a passivating contact structure utilizing HfO2 reveals a strong post-deposition annealing temperature dependence, with the lowest resistance achieved below 375 °C, followed by a decrease in performance as temperature increases towards the optimal temperature for passivation (475 °C). Limitations of the contact structure used are discussed.

Hafnium oxide: A thin film dielectric with controllable etch resistance for semiconductor device fabrication

Thin film dielectrics are ubiquitous in the manufacture of electronic devices and are frequently deposited and etched away at various stages of device fabrication. We demonstrate that hafnium oxide (HfO2) thin films grown via atomic layer deposition on silicon and silicon pre-coated with aluminum oxide (Al2O3) have etch resistance properties, which can be tuned simply by changing the post-deposition annealing temperature. The etching rates of films in hydrofluoric acid (HF) solutions were found to be dependent on annealing temperature, with the etch rate decreasing with increasing temperature. A transition region in the etch rate was identified between 300 and 350 °C, corresponding to the crystallization of the HfO2 films, as identified via x-ray diffraction. HfO2 films deposited directly onto silicon annealed above 350 °C were resistant to 10% HF solutions over the course of several hours. In the case of Si/Al2O3/HfO2 stacks, closer inspection reveals the existence of channels, which reduces the etch resistance of HF acid, as evidenced by tetramethylammonium hydroxide etching of the silicon substrate. Crystallized HfO2 can be used to protect other dielectrics in device processing, and we demonstrate its use in single-sided fabrication of patterned structures of Al2O3, which can control the effective charge-carrier lifetime in silicon wafers for use in modulating THz and mm-wave radiation.

Influence of post-deposition annealing temperature on structural and electrical properties of TiW contact thin films

Influence of post-deposition annealing temperature on structural and electrical properties of TiW contact thin films

Effects of post-deposition annealing temperature and atmosphere on interface properties in ALD Al2O3/plasma oxidation GeO x /(111) and (100) n-Ge MOS structures

In this work, the effects of post-deposition annealing (PDA) on Al2O3/GeO x /(111) and (100) n-Ge structures are experimentally studied with changing annealing temperatures from 300 °C to 650 °C in a vacuum, N2 and O2 atmosphere in order to clarify the stability of the MOS interface properties under high-temperature annealing. A decrease in D it and an increase in the oxide capacitance with increasing PDA temperature is observed up to 500 ∼ 600 °C, depending on the annealing atmosphere and surface orientation. The minimum D it of ∼3 × 1011 eV−1cm−2 is achieved for (111) Ge after PDA at 550 °C and 600 °C in N2/O2 or vacuum. This trend is similar to the (100) MOS interfaces and a similar amount of minimum D it is obtained. These results suggest that the present Al2O3/GeO x /Ge interfaces are suitable for the formation of the Ge-On-insulator (GOI) back interfaces by the wafer bonding process in the Smart-cut, where high-temperature annealing is indispensable.

Electrical properties of amorphous Zn–Sn–O thin films depending on composition and post-deposition annealing temperature near crystallization temperature

This study investigated the crystallization and electrical properties of atomic layer deposited Zn–Sn–O (ZTO) thin films. Sn 42 at% ZTO thin film showed the best thermal stability and electrical properties due to a change in the sub-gap states.

Deposition of sputtered NiO as a p-type layer for heterojunction diodes with Ga2O3

The characteristics of sputtered NiO for use in pn heterojunctions with Ga2O3 were investigated as a function of sputtering parameters and postdeposition annealing temperature. The oxygen/ nickel and Ni2O3/NiO ratios, as well as the bandgap and resistivity, increased as a function of O2/Ar gas flow ratio. For example, the bandgap increased from 3.7 to 3.9 eV and the resistivity increased from 0.1 to 2.9 Ω cm for the O2/Ar ratio increasing from 1/30 to 1/3. By sharp contrast, the bandgap and Ni2O3/NiO ratio decreased monotonically with postdeposition annealing temperatures up to 600 °C, but the density of films increased due to a higher fraction of NiO being present. Hydrogen is readily incorporated into NiO during exposure to plasmas, as delineated by secondary ion mass spectrometry measurements on deuterated films. The band alignments of NiO films were type II-staggered gaps with both α- and β-Ga2O3. The breakdown voltage of NiO/β-Ga2O3 heterojunction rectifiers was also a strong function of the O2/Ar flow ratio during deposition, with values of 1350 V for 1/3 and 830 V for 1/30.

Hydrogen-Doping-Enabled Boosting of the Carrier Mobility and Stability in Amorphous IGZTO Transistors.

This study investigated the effect of hydrogen (H) on the performance of amorphous In-Ga-Zn-Sn oxide (a-In0.29Ga0.35Zn0.11Sn0.25O) thin-film transistors (TFTs). Ample H in plasma-enhanced atomic layer deposition (PEALD)-derived SiO2 can diffuse into the underlying a-IGZTO film during the postdeposition annealing (PDA) process, which affects the electrical properties of the resulting TFTs due to its donor behavior in the a-IGZTO. The a-In0.29Ga0.35Zn0.11Sn0.25O TFTs at the PDA temperature of 400 °C exhibited a remarkably higher field-effect mobility (μFE) of 85.9 cm2/Vs, a subthreshold gate swing (SS) of 0.33 V/decade, a threshold voltage (VTH) of -0.49 V, and an ION/OFF ratio of ∼108; these values are superior compared to those of unpassivated a-In0.29Ga0.35Zn0.11Sn0.25O TFTs (μFE = 23.3 cm2/Vs, SS = 0.36 V/decade, and VTH = -3.33 V). In addition, the passivated a-In0.29Ga0.35Zn0.11Sn0.25O TFTs had good stability against the external gate bias duration. This performance change can be attributed to the substitutional H doping into oxygen sites (HO) leading to a boost in ne and μFE. In contrast, the beneficial HO effect was barely observed for amorphous indium gallium zinc oxide (a-IGZO) TFTs, suggesting that the hydrogen-doping-enabled boosting of a-IGZTO TFTs is strongly related to the existence of Sn cations. Electronic calculations of VO and HO using density functional theory (DFT) were performed to explain this disparity. The introduction of SnO2 in a-IGZO is predicted to cause a conversion from shallow VO to deep VO due to the lower formation energy of deep VO, which is effectively created around Sn cations. The formation of HO by H doping in the IGZTO facilitates the efficient connection of atomic states forming the conduction band more smoothly. This reduces the effective mass and enhances the carrier mobility.

Effects of post-deposition annealing temperatures in argon ambient on structural, optical, and electrical characteristics of RF magnetron sputtered gallium oxide films

Different post-deposition annealing temperatures were carried out in argon ambient to investigate the corresponding effects onto structural, morphological, optical, and electrical characteristics of RF magnetron sputtered gallium oxide (Ga2O3) films. Cubic phase of γ-Ga2O3 was transformed to mixed phases of cubic and monoclinic phases of β-Ga2O3 as the temperature was increased from 400 to 800 °C before became fully β-Ga2O3 phases at 1000 °C. Oxygen vacancies and oxygen interstitials were formed, generating deep energy levels in band gap of the Ga2O3 films. Findings revealed the acquisition of the highest current density in the Ga2O3 film annealed at 400 °C as a consequence of the highest density (J) of dislocation and oxygen vacancies in the film. Nonetheless, the formation of a thicker interfacial layer and location of oxygen vacancies in the film annealed at 1000 °C have caused minute increase in the J surpassing that of 800 °C at a gate voltage greater than 15 V.

Influence of deposition power and annealing on the performance of RF-sputtered SnS for infrared photodetection

Tin sulfide has shown their great potential in electronic and photonic systems due to its unique optoelectronic properties, less toxic nature, cost-effective and economically earth-abundant elements. The multivalence of Sn and stereochemical activity endow it with rich phase spaces and susceptible internal structures, which in turn directly affect its properties. In this paper, optimization studies towards the influence of RF power and post-deposition annealing temperature on the micro structure and photodetection performance of SnS are achieved by RF magnetron sputtering method. The structural characterizations confirm the significance of RF power for phase formation and photoelectric conversion ability. The optical band gap shifts from 1.41 eV to 1.30 eV as RF power increasing from 30 W to 50 W, in the meantime, the optoelectronic performances such as responsivity and specific detectivity are subsequently improved to be 226.55 mA/W and 1.76 × 1010 Jones. Further, the variations in infrared photodetection performance correlated with the annealing temperature exhibite a more well-behaved photoresponse at 300 °C. The results pave the way to discern the growth − structure − property relationships and then guide potencial applications of tin sulfide family.

A new approach for alkali incorporation in Cu2ZnSnS4 solar cells

The addition of alkali elements has become mandatory for boosting solar cell performance in chalcogenide thin films based on kesterites (Cu2ZnSnS4, CZTS). A novel doping process is presented here, that consists in the incorporation of sodium or lithium during the deposition of the CdS buffer layer, followed by a post-deposition annealing (PDA). As the doping route leads to more efficient devices in comparison with the undoped reference sample, the influence of PDA temperature was also investigated. Compositional profiling techniques, time-of-flight secondary ion mass spectrometry (TOF-SIMS) and glow discharge optical mission spectroscopy (GDOES), revealed a dependence of the alkaline distribution in kesterites with the PDA temperature. Although the doping process is effective in that it increases the alkaline concentration compared to the undoped sample, the compositional profiles indicate that a significant proportion of Li and Na remains ‘trapped’ within the CdS layer. In the 200 °C–300 °C range the alkali profiles registered the higher concentration inside the kesterite. Despite this, an additional alkali accumulation close to the molybdenum/fluorine doped tin oxide substrate was found for all the samples, which is frequently related to alkali segregation at interfaces. The addition of both, lithium and sodium, improves the photovoltaic response compared to the undoped reference device. This is mainly explained by a substantial improvement in the open-circuit potential (V oc) of the cells, with best devices achieving efficiencies of 4.5% and 3% for lithium and sodium, respectively. Scanning-electron microscopy images depicted a ‘bilayer structure’ with larger grains at the top and small grains at the bottom in all samples. Moreover, the calculated bandgap energies of the CZTS films account for changes in the crystallographic order-disorder of the kesterites, more related to the PDA treatment rather than alkali incorporation. Even if further optimization of the absorber synthesis and doping process will be required, this investigation allowed the evaluation of a novel strategy for alkali incorporation in kesterite based solar cells.

Low-Temperature Route to Direct Amorphous to Rutile Crystallization of TiO2 Thin Films Grown by Atomic Layer Deposition

The physicochemical properties of titanium dioxide (TiO2) depend strongly on the crystal structure. Compared to anatase, rutile TiO2 has a smaller bandgap, a higher dielectric constant, and a higher refractive index, which are desired properties for TiO2 thin films in many photonic applications. Unfortunately, the fabrication of rutile thin films usually requires temperatures that are too high (>400 °C, often even 600–800 °C) for applications involving, e.g., temperature-sensitive substrate materials. Here, we demonstrate atomic layer deposition (ALD)-based fabrication of anatase and rutile TiO2 thin films mediated by precursor traces and oxide defects, which are controlled by the ALD growth temperature when using tetrakis(dimethylamido)titanium(IV) (TDMAT) and water as precursors. Nitrogen traces within amorphous titania grown at 100 °C inhibit the crystal nucleation until 375 °C and stabilize the anatase phase. In contrast, a higher growth temperature (200 °C) leads to a low nitrogen concentration, a high degree of oxide defects, and high mass density facilitating direct amorphous to rutile crystal nucleation at an exceptionally low post deposition annealing (PDA) temperature of 250 °C. The mixed-phase (rutile–brookite) TiO2 thin film with rutile as the primary phase forms upon the PDA at 250–500 °C that allows utilization in broad range of TiO2 thin film applications.

Annealing temperature dependence of band alignment of NiO/β-Ga2O3

The band alignment of sputtered NiO on β-Ga2O3 was measured by x-ray photoelectron spectroscopy for post-deposition annealing temperatures up to 600 °C. The band alignment is type II, staggered gap in all cases, with the magnitude of the conduction and valence band offsets increasing monotonically with annealing temperature. For the as-deposited heterojunction, ΔE V = −0.9 eV and ΔE C = 0.2 eV, while after 600 °C annealing the corresponding values are ΔE V = −3.0 eV and ΔE C = 2.12 eV. The bandgap of the NiO was reduced from 3.90 eV as-deposited to 3.72 eV after 600 °C annealing, which accounts for most of the absolute change in ΔE V−ΔE C. Differences in thermal budget may be at least partially responsible for the large spread in band offsets reported in the literature for this heterojunction. Other reasons could include interfacial disorder and contamination. Differential charging, which could shift peaks by different amounts and could potentially be a large source of error, was not observed in our samples.

(Invited) Energy Enhanced Atomic Layer Deposition (EEALD)

Atomic layer deposition (ALD) is a layer by layer chemical vapor deposition (CVD) technique based on alternating purge-separated self-limiting surface reactions. ALD offers inherent atomic scale controlled growth of high quality conformal thin films at relatively low temperatures. A low thermal budget is often critical in microelectronics processing, such as for back-end-of-line processing, 3D integration, deposition on glass or flexible substrates for large area electronics, avoiding unwanted diffusion, and maintaining stable flat band voltages, effective work functions, threshold voltages, and effective oxide thickness in metal/insulator/metal (MIM) and metal/oxide/semiconductor (MOS) device structures. However, low deposition temperature can lead to incorporation of excess -OH groups or other residual impurities from unreacted ligands and result in poor stoichiometry of ALD films. Poor stoichiometry may in turn lead to sub-optimal physical, optical, and electrical properties. A number of approaches may be used to reduce impurities, increase density, improve properties, and achieve the desired morphology of ALD films. An obvious approach is to increase deposition temperature, however this may move a process out of the ALD window into the CVD regime, negating many of the benefits of ALD. The most common approach is post-deposition annealing (PDA) at elevated temperatures. The PDA temperatures that are typically required however, can exceed the maximum temperature limitations of the substrate or previously formed electronics. To maintain the low thermal budget of ALD while maximizing film properties, performing annealing during, rather than after, deposition can be beneficial. An alternate approach to help drive reactions and reduce impurity / ligand incorporation is thus to add extra energy as part of each (or every few) ALD supercycles. Methods to date include in-situ rapid thermal (MTA, DADA, etc.) annealing, flash lamp annealing, plasma exposure, and UV exposure. I will collectedly refer to these techniques as energy enhanced ALD (EEALD). [1-13] (Note that these methods are distinct from plasma enhanced ALD (PEALD), an excellent review of which can be found in [14].) Documented benefits of the various forms of EEALD include higher GPC, denser films, lower temperature, improved dielectric constant and refractive index, lower leakage, lower residual impurities. A potential downside of energy enhancement is the additional time required to implement these steps into the ALD super-cycle, particularly cool down time when in-situ annealing is incorporated. This invited talk will describe, compare, and contrast these various techniques focusing on mechanisms (thermal vs. chemical), placement in ALD supercycle, benefits and drawbacks, and challenges to be addressed in finding the ideal EE-ALD technique. Finally, I will introduce an entirely new method of EE-ALD. J.F. Conley, Jr., Y. Ono, D.J. Tweet, Appl. Phys. Lett. 84(11), 1913-1915 (2004).J.F. Conley, Jr., D.J. Tweet, Y. Ono, and G. Stecker, in High-k Insulators and Ferroelectrics for Advanced Microelectronic Devices, R.M. Wallace, D. Landheer, M. Houssa, and J. Morais, eds., MRS Proc. Vol. 811, 5 (2004).J.F. Conley, Jr., Y. Ono, D. Tweet, G. Stecker, R. Solanki, and W.W. Zhuang, in Physics and Technology of High-k Gate Diectrics II, S. Kar, R. Singh, D. Misra, H. Iwai, M. Houssa, J. Morais, and D. Landheer, eds., ECS Proc. Vol. 2003-22, 11 pgs.K.H. Holden, S.M. Witsel, P.C. Lemaire, and J.F. Conley, Jr. in preparation (2022).Henke et al., ECS J. Sol. Sta. Sci. Tech. 4(7), 277 (2015).R.D. Clark et al., ECS Transactions, 41(2), 79 (2011).Miikkulainen et al., ECS Tran. 80(3), 49 (2017).Chalker et al., ECS Tran. 69(7), 139 (2015).Kwak, Y.-H. Lee, and B.-H. Choi, Appl. Surf. Sci. 230, 249 (2004).Kim et al., Electrochemical and Solid-State Lett. 14(4), H146 (2011)No et al., J. ECS 153(6), F87 (2006).Shih et al., Sci. Rep. 7(1), 39717 (2017).Österlund et al. Vac. Sci. Tech. A 39, 032403 (2021).Ueda et al., Appl. Surf. Sci. 554, 149656 (2021).Profijt, et al., J. Vac. Sci. Technol. A 29(5), 050801 (2011).