An ultrathin Zr(Ge) alloy film as an exhaustion interlayer combined with Cu(Zr) seed layer for the Cu/porous SiOC:H dielectric integration

Abstract

A highly reliable interface of an ultrathin Zr(Ge) exhaustion interlayer between Cu(Zr) film and porous SiOC:H (p-SiOC:H) dielectric has been developed in the present work. After being processed at a moderate elevated temperature (say, 450 °C), a self-formed nanomultilayer of CuGex/ZrOx(ZrSiyOx) was produced at the interface of Cu(Zr)/p-SiOC:H film stacks, which showed strong ability to effectively hinder Cu atoms diffusion into p-SiOC:H film and free Si atoms diffusion into Cu film. The mechanism involving the thermal stability of the films system is analyzed based on detailed characterization studies.

Self-Formed Diffusion Layer in Cu(Re) Alloy Film for Barrierless Copper Metallization

“…Due to the difficulty in achieving uniform depositions of ultra-thin barrier layers, more attention has been paid to self-formed diffusion barriers (barrierless metallization) in recent years [13][14][15]. The self-formed barrier layer offers low electrical resistivity, resistance to Cu diffusion, resistance to electromigration and compatibility with conformal deposition techniques [16][17][18][19][20][21]. A self-formed barrier scheme is achieved by doping with diffusion barrier elements as well as their nitrides and carbides, such as Ti, Zr, Mn and WN [22][23][24][25][26][27][28].…”

Nano-grained ZrB2 thin films as a high-performance diffusion barrier in Cu metallization

“…Refractory transition metals, such as, Ta, Ti, Zr, Ru, characteristic of low resistivity and high thermal stability, become the research focus. [5][6][7][8] Generally, pure metal thin lms possess polycrystalline structure in which Cu atoms can diffuse along the grain boundaries and react with Si substrates at lower temperature. For example, 20 nm thick Ru diffusion barrier became failure at 450 C. 9 The current barrier materials adopted in Cu interconnection is Ta/TaN bilayer with a total thickness of 100 nm in which Ta serves as a glue layer and TaN is indeed the barrier layer.…”

Ultrathin CuSiN/p-SiC:H bilayer capping barrier for Cu/ultralow-k dielectric integration

“…Finally, a porous ULK a-SiOC: H ͑IMD͒ film was deposited on the surface of both groups of the films by the same PECVD technique. 11 Samples ͓Si/ SiO 2 ͑250 nm͒/TaN ͑10 nm͒/Ta ͑15 nm͒/Cu ͑600 nm͒/͓CuSiN/ a-SiC: H ͑40 nm͒ or a-SiC: H ͑40 nm͔͒/a-SiOC: H ͑400 nm͔͒ were then annealed in a vacuum furnace in the temperature range of 400-450°C for 4 h to study the diffusion barrier properties of the films. The k-value of the annealed a-SiC: H film and ULK a-SiOC: H ͑IMD͒ film were about 3.3 and 2.1, respectively.…”