Plasma Etching of ITO Thin Films Using a CH₄/H₂ Gas Mixture

Abstract

Plasma etching of ITO (In2O3:Sn indium tin oxide) thin films has been performed using a CH4/H2 plasma. Etching occurs above a substrate temperature (T s) of 60°C and the etch rate increases with increasing T s, while amorphous like or polymer-like carbon deposits onto the ITO films below 60°C. The apparent activation energy of the etching is 4.12 kcal/mol (0.18 eV). This small activation energy suggests that the desorption of produced volatiles is the rate-limiting process. Fine ITO patterns (1.5 µmL/S) were obtained using this gas mixture.

Fast and smooth etching of indium tin oxides in BCl3/Cl2 inductively coupled plasmas

“…The addition of CF 4 by more than 4% leads to a significant increase in the etch rate. 11 The morphology of the etched surfaces was examined by AFM. The etch rate stabilizes as the %CF 4 is increased further.…”

“…[11][12][13][14] However, polymeric hydrocarbon films may be easily deposited on the etched surface and impede the etching process. 11-17 CH 4 -containing organic gases mixed with H 2 or Ar are often used because etch products such as In͑CH 3 ͒ x and Sn͑CH 3 ͒ y have relatively high volatility.…”

Identifying new absorber materials for EUV photomasks

“…Notably, the reactions happening in a plasma environment are complex and often involve multistep intermediate reactions with transient species. Instead, this paper explores very simple reactions (example reactions d, e, f in Table 1), where the metal is in its atomic solid standard state (M), gases are in their atomic states (F, Cl, H, O, C), bromine is in its atomic liquid state (Br), and methyl is in its molecular gas state (CH3) [16,[24][25][26][27]. From these general reactions, ΔGrxn can be calculated using the standard molar enthalpies of formation ΔfH°and the standard molar entropies S°.…”

Indium Tin Oxide optical access for magnetic tunnel junctions in hybrid spintronic–photonic circuits

“…The Cr disks have nominal diameters from 20 up to 500 nm. Induced coupled plasma (ICP) has been applied successfully to etch ITO [6,7,8] After IBE, the ITO pillar diameter was measured from SEM images shown in Figure 5, to reveal a lateral size reduction of 15-20 nm. This is the result of trimming happening during the IBE process and is common to both ITO and Ta process flows.…”