Atomic layer deposition of Er2O3 thin films from Er tris-guanidinate and water: process optimization, film analysis and electrical properties

Abstract

For the first time, the combination of the homoleptic erbium tris-guanidinate metalorganic complex ([Er(NMe 2 -Guan) 3 ]) simply with water yielded high quality Er 2 O 3 thin films on Si(100) substrates employing the atomic layer deposition (ALD) process. The process optimization to grow good quality Er 2 O 3 layers was performed by varying the Er precursor pulse time, water pulse time and purge time.The high reactivity of the Er compound towards water and good thermal stability in the temperature range of 150-275 C (ALD window) resulted in homogeneous, stoichiometric Er 2 O 3 layers with high growth rates (1.1 Å per cycle) and the as-deposited films crystallized in the cubic phase. The saturation behavior at different temperatures in the ALD window and the linear dependence of film thickness as a function of precursor pulse time confirmed the true ALD process. The potential of Er 2 O 3 thin films as gate dielectrics was verified by performing capacitance-voltage (C-V) and current-voltage (I-V) measurements. Dielectric constants estimated from the accumulation capacitance were found to be in the range of 10-13 for layers of different thicknesses (15-30 nm).

Cyclopentadienyl Precursors for the Atomic Layer Deposition of Erbium Oxide Thin Films

“…The films deposited with water contained an excess of oxygen as compared to the films deposited with ozone (Er/O ratio = 0.55 and 0.66 with water and ozone, respectively). Interestingly, in the Er(NMe 2 ‐Guan) 3 /water study, XPS analysis revealed the presence of a signal at 532.9 eV that can be associated with –OH bonding within erbium hydroxide [Er(OH) 3 ] . A similar signal was observed here in the XPS image of the Er 2 O 3 thin films deposited with water.…”

“…Self‐limiting growth was confirmed using water as the oxygen source at 300°C but the later study on the ozone process did not present evidence of self‐limiting growth at that temperature . More recently, Er 2 O 3 thin films were grown by ALD using the homoleptic guanidinate erbium precursor Er(NMe 2 ‐Guan) 3 and water as the oxygen source . The thermal stability of Er(NMe 2 ‐Guan) 3 was limited to 250°C and the growth rate was 1.1 Å per cycle.…”

Water assisted atomic layer deposition of yttrium oxide using tris(N,N′-diisopropyl-2-dimethylamido-guanidinato) yttrium(iii): process development, film characterization and functional properties

“…Thus, a strong oxidizing agent such as ozone had to be used as reactive coreactant at high deposition temperatures of 350 C which yielded growth rates of only 0.22Å per cycle. 20, 21 We build upon our recent advances in new ALD process development and here in we report a new water assisted ALD process for Y 2 O 3 thin lms. The ALD characteristics were veried and the deposited thin lms were characterized with respect to their crystallinity, morphology and composition.…”

Development of Volatile Inorganic Compounds and Their Application for Chemical Vapour Deposition of Metal and Metal Oxide Thin Films

“…In the coming years, a rich selection of guanidinate metal complexes will likely emerge as their thermal properties become more understood and predictable and will be developed for CVD and ALD. [32][33][34][35][36] Taylor Pigeon contributed supporting information and data.…”

“…Si ( [34] Abbreviations: guan = [( i PrN)2C(NMe2)];, not reported = NR Table 2.3.2 shows that not only are the process temperatures lower, but also the film growth rates are much lower. The tris(N,N'-diisopropyl-2dimethylamido-guanidinato) indium(III) complex is an excellent example of such a compound.…”