Low-k dielectrics

The next three chapters (Chapters 9-11) focus on the deposition of nano-structured or microstructured films and entities. Porous oxide thin films are, for example, of great interest due to potential application of these films as low-K dielectrics and in sensors, selective membranes, and photovoltaic applications. One of the key challenges in this area is the problem of controlling, ordering, and combining pore structure over different length scales. Chapter 9 provides an introduction and discussion of evaporation-induced self-assembly (EISA), a method that combines sol-gel synthesis with self-assembly and phase separation to produce films with a tailored pore structure. Chapter 10 describes how nanomaterials can be used as soluble precursors for the preparation of extended... 

Each of these polymers exploit the ability of the group 10 metal catalysts used to tolerate functional groups and to copolymerise norbomene monomers bearing esters etc. into the polymer backbone. In the case of low-k dielectric polymers (Avatrel ) low levels (2-10 mol %) of 5-triethoxysilylnorbomene are used to impart good adhesive properties, the remaining 90+% of the monomer being a 5-alkylnorbomene. The alkylnorbomene is selected to tailor... 

An excihng new scientific direction emerged in the 1980s and 1990s for exploring molecular sieves as advanced solid state materials. In a 1989 review, Ozin et al. [88] speculated that zeolites (molecular sieves) as microporous molecular electronic materials with nanometer dimension window, channel and cavity architecture represent a new fronher of solid state chemistry with great opportunihes for innovahve research and development . The applicahons described or envisioned included molecular electronics, quantum dots/chains, zeolite electrodes, batteries, non-linear ophcal materials and chemical sensors. More recently there have been significant research reports on the use of zeolites as low k dielectric materials for microprocessors [89]. 

The scarcity of efficacious insulation candidates prompted the Semiconductor Industry Association to identify the criticality of low-k dielectric material development. Thus, in June 1995, Dow made a business commitment to invent a new material specifically tailored for the interconnect application. Specific performance targets were defined based on interactions with the industry, experience gained through Dow s earlier benzocyclobutene-based systems, finite element analysis of the anticipated interconnect structures, and principles of material sciences. 

Peters L (1998) Pursuing the Perfect Low-K Dielectric, Semiconductor International 21(10) 64-67... 

The data and methods discussed in the previous sections show the power of positron and positronium annihilation methods for the characterization of porous materials and low-k dielectrics in particular. The obvious question is, whether this power can be harnessed for an online diagnostic tool in a semiconductor production line. Such a tool should be reliable, compatible with existing processes, rapid, and not more complex than any other system. 

Three polyarylene ethers having a M > 10,500 with dielectric constants of around 2.5 were prepared and used as low k dielectric layers in electronic applications. 

Weber [6] devised a method for repairing porous low k dielectric films by sealing with polydentate ligands, such as ethylene diamine tetraacetic. 

FIGURE 1.6 Incorporation of hard masks to protect the low-k dielectric materials (from Ref 23). 

What still remains a challenge to a CMP system for the integration of low-k dielectric materials ... 

Ong P, Ponoth S, Economikos L, Sakamoto A, Flong DPI, Chae M, Rhee SH, Nicholson LM, Landers W, Werking J, Li B, Chen F, Sankaran S. Cu CMP with direct polish on ultra-low-k dielectric film k 2.4) for 45 nm technology node. ICPT Oct 2006. 

Sato S et al. Newly developed electrochemical polishing process of copper inlaid in frangile low-k dielectrics. lEDM. 2001. p 4.4.1-4.4.4. 

Shamiryan D, Abell T, Lacopi F, Maex K. Low-k dielectric materials. Mater Today... 

Fayolle M, Passemard G, Assous M, Louis D, Beverina A, Gobil Y, Cluzel J, Arnaud L. Integration of copper with an organic low-k dielectric in 0.12-mm node interconnect. Microelectr Eng 2002 60(1-2) 119-124. 

Schulze K, Schulz SE, Friihauf S, Korner H, Seidel U, Schneider D, Gessner T. Improvement of mechanical integrity of ultra low k dielectric Stackand CMP compatibility. Microelectr Eng 2004 76(l-4) 38-45. 

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