Optical spectroscopic study of the SiN∕HfO2 interfacial formation during rf sputtering of HfO2

Abstract

High-k stacks formed by chemical-vapor-deposited SiN and high-pressure sputtered HfO2 in either O2 or Ar atmosphere have been studied. The introduction of a SiN layer is proposed to prevent the uncontrollable SiO2 growth while sputtering. The formation of Si–O bonds after the sputtering of the HfO2 film in O2 atmosphere was observed by infrared spectroscopy. Optical diagnosis of the plasma demonstrated a high density of O radicals in the system when working with O2. The small radius and high reactivity of these O radicals are the source of the SiN oxidation. However, the structure of the SiN film is preserved during Ar sputtering.

Scandium oxide deposited by high-pressure sputtering for memory devices: Physical and interfacial properties

“…Analogous results can be extracted for deposited SiN x . 19 The increase in the absorbance in the 400-500 cm −1 range can be associated to Sc-O bonds. This is confirmed by FTIR spectra before and after ScO x deposition in Fig.…”

“…This technique has been used to grow high-T c superconductors 15,16 and we successfully used it to deposit TiO 2 and HfO 2 high-k dielectric films. [17][18][19] It also permits ternary compounds to be grown with a multitarget system which is a very interesting characteristic to pursue scandates research.…”

Nano-laminate vs. direct deposition of high permittivity gadolinium scandate on silicon by high pressure sputtering

“…Depositions are performed at low temperatures and pressures in the 100 Pa range, three orders of magnitude over conventional sputtering systems [13,14]. The sputtered atoms emitted from the target collide with the gas medium, lose their energy and thermalize within a short distance 3 (0.1-0.3 cm) [15,16].…”

Interface engineering by metal electrode scavenging of Gd<inf>2</inf>O<inf>3</inf> films sputtered on Si

“…Since they appear in the 390-470 region they might be overshadowed by the Ar I peaks. One of the strongest emission lines of O I is located at 394.7 nm [4] without any Ar peak nearby, so it is a perfect region to check oxygen excitation. When focusing on that wavenumber, we can see a weak emission increase with rf power.…”

“…. Figure 1.a shows that when sputtering in pure Ar at a fixed power of 30W there are features due to Ar I (non-ionized) located at 400-450 nm [4], Ar II (singly ionized) between 450-490 nm [4], and also Gd I and Gd II in the 290-410 nm region [5]. In fact, these features are present (with a lower intensity) even when using an rf power of only 10W.…”