Pellicle membrane and method of forming the same
A method of forming a pellicle includes forming a protective film surrounding a membrane to form a pellicle membrane using a plasma enhanced atomic layer deposition (PEALD) process, in which the membrane includes a network of carbon nanotubes, the PEALD process is performed by a plurality of cycles, and each of the cycles includes igniting a plasma in a deposition chamber, after igniting the plasma, introducing a silicon-based precursor into the deposition chamber, purging the silicon-based precursor, introducing a reactant gas into the deposition chamber, and purging the reactant gas, placing the pellicle membrane on a filter membrane, transferring the pellicle membrane from the filter membrane to a pellicle border, attaching the pellicle border to a pellicle frame, and mounting the pellicle frame onto a photomask comprising a pattern region.
1 . A method of forming a pellicle, comprising:
forming a protective film surrounding a membrane to form a pellicle membrane using a plasma enhanced atomic layer deposition (PEALD) process, wherein the membrane comprises a network of carbon nanotubes, the PEALD process is performed by a plurality of cycles, and the cycles start with a step which comprises:
igniting a plasma in a deposition chamber, wherein igniting the plasma comprises:
simultaneously introducing a purge gas and a nitrogen-containing reactant gas including nitrogen into the deposition chamber to generate the plasma comprising a plurality of ionized nitrogen-containing reactant within the deposition chamber, the plasma converts sp2 hybrid orbital of carbon atoms of the network of carbon nanotubes to sp3 hybrid orbital, the purge gas comprises: helium (He), argon (Ar), xenon (Xe), or a combination thereof;
after igniting the plasma, and after simultaneously introducing the purge gas and the nitrogen-containing reactant gas, introducing a silicon-based precursor into the deposition chamber;
purging the silicon-based precursor;
introducing the nitrogen-containing reactant gas into the deposition chamber; and
purging the nitrogen-containing reactant gas;
placing the pellicle membrane on a filter membrane;
transferring the pellicle membrane from the filter membrane to a pellicle border;
attaching the pellicle border to a pellicle frame; and
mounting the pellicle frame onto a photomask comprising a pattern region.
2 . The method of claim 1 , wherein after purging the silicon-based precursor, a residue of the silicon-based precursor stays in the deposition chamber.
3 . The method of claim 1 , further comprising:
introducing the nitrogen-containing reactant gas into the deposition chamber during igniting the plasma such that the plasma is ignited from the nitrogen-containing reactant gas.
4 . The method of claim 1 , wherein the plasma is present during introducing the silicon-based precursor.
5 . The method of claim 1 , wherein the plasma includes capacitively coupled plasma (CCP), inductively coupled plasma (ICP), microwave induce plasma (MIP), and hollow cathode plasma (HCP).
6 . The method of claim 1 , wherein the plasma is absent during introducing the silicon-based precursor.
7 . The method of claim 1 , wherein each of the cycles has a growth per cycle (GPC) of more than one atomic layer thickness.
8 . The method of claim 1 , wherein introducing the silicon-based precursor into the deposition chamber comprises:
flowing the purge gas simultaneously.
9 . The method of claim 1 , wherein the nitrogen-containing reactant is nitrogen (N 2 ), ammonia (NH 3 ), N 2 O, NO 2 , or a combination thereof.
10 . The method of claim 1 , wherein simultaneously introducing the purge gas and the nitrogen-containing reactant gas is performed for a first duration, introducing the silicon-based precursor into the deposition chamber is performed for a second duration, and the second duration is greater than the first duration.
11 . The method of claim 1 , wherein simultaneously introducing the purge gas and the nitrogen-containing reactant gas is performed for a first duration, introducing the nitrogen-containing reactant gas into the deposition chamber is performed for a third duration, the third duration is greater than the first duration.
12 . The method of claim 1 , wherein the pellicle frame comprises a round shape.
13 . The method of claim 1 , wherein the pellicle frame comprises a rectangular shape.
14 . The method of claim 1 , wherein the pellicle frame is Al—Ti alloy.
15 . A method for a lithography process, comprising:
providing a pellicle including a pellicle membrane, wherein the pellicle membrane includes at least a network of a plurality of carbon nanotubes, at least one of the plurality of carbon nanotubes including a core nanotube and a protective film surrounding the core nanotube, the protective film is formed by a deposition process which starts with a step including igniting a plasma, igniting the plasma comprises:
simultaneously introducing a purge gas and a nitrogen-containing reactant gas including nitrogen into a deposition chamber to generate the plasma comprising a plurality of ionized nitrogen-containing reactant within the deposition chamber, the plasma converts sp2 hybrid orbital of carbon atoms of the network of carbon nanotubes to sp3 hybrid orbital, the purge gas comprises: helium (He), argon (Ar), xenon (Xe), or a combination thereof;
after simultaneously introducing the purge gas and the nitrogen-containing reactant gas, introducing a precursor gas into the deposition chamber;
mounting the pellicle onto a photomask, wherein the photomask includes a patterned region;
loading the photomask having the pellicle mounted thereupon into a lithography system;
loading a semiconductor wafer onto a substrate stage of the lithography system; and
performing a lithography exposure process to transfer a pattern of the patterned surface from the photomask to the semiconductor wafer.
16 . The method of claim 15 , wherein the deposition process is plasma enhanced atomic layer deposition (PEALD) process.
17 . The method of claim 15 , wherein the precursor gas comprises Tris(dimethylamido) silane (3DMASi), Tetrakis(dimethylamido) silane (TDMASi), Bis(diethylamino) silane (BDEAS), (BTBAS), bis(tert-butylamido) silane bis(dimethylamido) silane (BDMAS), bis(ethylmethylamino) silane (BEMAS), Diaminosilane (SiH 2 (NH 2 ) 2 ), Silane (SiH 4 ), Disilane (Si 2 H 6 ), Dimethyldichlorosilane (DMDCS), Monochlorosilane (MCS), Dichlorosilane (DCS), Hexachlorodisilane (Si 2 Cl 6 ), Di(isopropylamino) silane (DIPAS), Di(sec-butylamino) silane (DSBAS), Tetrakis(ethylamido) silane (TEASi), TetraethylorthoSilicate (TEOS), Tris(isopropyl)aminosilane (TIPAS), Trimethylsilane (TMS), Triisopropylsilane (TIPS), Tris(dimethylamino)chlorosilane (3DMASiCl), Tris(ethylmethylamido) silane (3EMAS), or Trisilylamine (N(SiH 3 ) 3 ).
18 . The method of claim 15 , wherein one of the plurality of cycles of the PEALD process forms an N/Si/N/Si arrangement.
19 . The method of claim 15 , further comprising:
purging the precursor gas; and
introducing the nitrogen-containing reactant gas into the deposition chamber after purging the precursor gas.
20 . The method of claim 15 , wherein introducing the precursor gas into the deposition chamber comprises:
generating a plasma from the precursor gas.