To extend directed self-assembly (DSA) of poly(styrene-b-methyl methacrylate) (PS-<i>b</i>-PMMA) for higher resolution, placement accuracy and potentially improved pattern line edge roughness (LER), we have developed a next-generation material platform of organic high-χ block copolymers (“HC series”, AZEMBLY<sup>TM</sup> EXP PME-3000 series). The new material platform has a built-in orientation control mechanism which enables block copolymer domains to vertically selforient without topcoat/additive or delicate solvent vapor annealing. Furthermore, sub-10 nm lines and spaces (L/S) patterning by two major chemoepitaxy DSA, LiNe and SMART<sup>TM</sup> processes, was successfully implemented on 12” wafer substrates by using the PME-3000 lamellar series. The results revealed that the new material platform is compatible with the existing PS-<i>b</i>-PMMA-based chemical prepatterns and standard protocols. We also introduced the built-in orientation control strategy to the conventional PS-<i>b</i>-PMMA system, producing a new generation of PS-b-PMMA materials with facile orientation control. The modified PS-<i>b</i>-PMMA (m-PS-<i>b</i>-PMMA) performed LiNe flow DSA yielding a comparable CD process window with improved LER/LWR/SWR after the L/S patterns were transferred into a Si substrate.
To extend scaling beyond poly(styrene-b-methyl methacrylate) (PS-b-PMMA) for directed self-assembly (DSA), high quality organic high-<sub>x</sub> block copolymers (HC series) were developed and applied to implementation of sub-10 nm L/S DSA. Lamellae-forming block copolymers (BCPs) of the HC series showed the ability to form vertically oriented polymer domains conveniently with the in-house PS-r-PMMA underlayers (AZEMBLY EXP NLD series) without the use of an additional topcoat. The orientation control was achieved with low bake temperatures (≤200 °C) and short bake times (≤5 min). Also, these process-friendly materials are compatible with existing 193i-based graphoepitaxy and chemoepitaxy DSA schemes. In addition, it is notable that 8.5 nm organic lamellae domains were amenable to pattern development by simple dry etch techniques. These successful demonstrations of high-<sub>x</sub> L/S DSA on 193i-defined guiding patterns and pattern development can offer a feasible route to access sub-10 nm node patterning technology.
Hardmasks are indispensable materials during pattern transfer to the desired substrates in the semiconductor
manufacturing process. Primarily there are two types of hardmask materials - organic and inorganic - and they can
be coated onto substrates or underlying materials either by a simple spin-on process or by more expensive methods
such as chemical vapor deposition (CVD), atomic layer deposition (ALD) and sputtering process. Most inorganic
hardmasks such as SiO2, SiON, SiN and TiN are deposited using the CVD process.
Future nodes require hardmasks with high etch resistance as the designs move from horizontal to vertical (3D). We
have reported novel spin-on metallic hardmasks (MHM) with comparable or higher etch resistance than SiO2.1-2 In
addition to high etch resistance, they are easy to remove using wet etch chemicals. The spin-on process offers high
throughput and commonly used spin tracks can be utilized; thereby reducing overall process costs when compared
Via-fill performance is also an important attribute of hardmask materials for these future nodes. Organic spin-on
materials, both siloxane- and carbon-based, are used in filling applications of deep via or deep trench fill, such as
those found in LELE double-patterning schemes. Inorganic materials deposited by either chemical vapor deposition
(CVD) or atomic layer deposition (ALD) have higher resistance to oxygenated plasma than organic materials, but
are hindered by their poor filling performance. Therefore, novel tungsten (W) containing MHM materials having
both good filling performance and higher resistance to oxygenated plasma than organic materials would be of value
in some filling applications. The present paper describes specific metal oxides useful for filling applications. In
addition to basic filling performance and etch resistance, other properties such as optical properties, outgas and shelf
life via forced aging etc. will be discussed.
Developable BARCs (DBARCs) are useful for implant layers because they eliminate the plasma etch step avoiding
damage to the plasma sensitive layers during implantation. It is expected that DBARC will also be used for non-implant
layers and double exposure technology. AZ has pioneered DBARC based on photosensitive cleave as well as
crosslink/decrosslink mechanisms. In this paper, we focus on various processing factors for 193nm DBARC and discuss
the influences of prewet, thickness, topography and substrates on lithographic performance. Prewet of DBARC before
resist coating deteriorated performance, however, it was resolved by modifying DBARC formulations. The optimized
DBARC showed both optical and lithographic performance comparable to conventional BARCs. DBARCs minimized reflection from the substrates and notching of patterns was improved observed on silicon oxide topography. This paper includes simulation, DBARC contrast curve analyses, and recent dry and immersion exposure results of DBARC.
Developable bottom anti-reflective coatings (DBARC) are an emerging litho material technology. The biggest
advantage of DBARC is that it eliminates the plasma etch step, avoiding damage to plasma sensitive layers during
implantation. AZ has pioneered developable BARC based on photosensitive cleave as well as crosslink/decrosslink
mechanisms. In this paper, we focus on the crosslink/decrosslink concept. DBARC/resist mismatching was corrected
both from process and formulation sides. The optimized DBARC showed comparable lithographic performance as
conventional BARCs. This paper provides the chemical concept of the photosensitive developable DBARCs,
approaches for DBARC/resist matching and performance of photosensitive DBARCs for 248 nm and 193 nm
exposures. Recent 193 nm immersion exposure results are also presented.
Second generation, radiation sensitive, developable 193 Bottom Antireflective coatings (DBARCs) are made solvent
resistant through a crosslinking mechanism activated during post apply bake (PAB) that is reversible by acid catalyzed
reaction upon exposure of the DBARC/resist stack. This allows coating the resists on the DBARC, after PAB, without
dissolution of the antireflective coating. This DBARC approach avoids the plasma etch breakthrough needed for
conventional bottom antireflective coatings which are irreversibly crosslinked, while maintaining excellent reflectivity
control, typically lower than 1% on bare Si. We will give an update on the performance our latest 193 nm DBARC
prototype materials used with different conventional alicyclic based 193 nm resists. For instance, using a binary mask
with conventional illumination several of our prototype DBARC formulations were able to resolve 120 nm trench
features with a 250 nm pitch.
We report about the development of a thick negative photoresist series, AZ<sup>(R)</sup> EXP 125nXT, and their use in
electroplating levels up to 160 μm thickness. The new photoresist series enables coatings of 5-120 μm with acceptable
uniformity and edge bead in a single coat step. 200 μm photoresist coating was achieved by a double coating processes.
The lithographic performance of the photoresists was evaluated using broad band aligners and steppers. Optimized
lithographic parameters to achieve straight and nearly vertical side wall profiles are reported. The photoresists show not
only excellent adhesion to copper with no surface treatment and electroplating tolerance in a variety of metal plating
solutions, but is also compatible with silicon and gold substrates. The photoresists have been found to be easily stripped
with no residues in solvent based stripper solutions.