Damage-less full molecular-pore-stack SiOCH (MPS) / Cu interconnect is developed to reduce effective k-value (k eff ).MPS with high endurance against plasma processes is introduced into both via and trench dielectrics without hard mask (HM). Low friction slurry and chemical modification of MPS surface by He-plasma treatment suppress defect generation during direct CMP of the MPS surface. The full-MPS interconnect with low-k (k=3.1) cap demonstrates 10% lower inter-line capacitance and 34% lower inter-layer capacitance than the full-SiOCH (k=3.0) interconnect with SiCN-cap (k=4.9). The effective k-value k eff reduces to 2.67 for the damage-less full MPS structure which is applicable to 32nm LSIs and beyond.

A novel cylinder-type metal-insulator-metal (MIM) capacitor in porous low-k film (CAPL) is proposed for embedded DRAMs (eDRAMs). The CAPL removes long bypass-contacts (BCT) with high resistance, which have been used to connect transistors with Cu interconnects by way of the MIM capacitor layer. A key technical challenge for the CAPL integration is control of pore structure in the low-k film to avoid metal contamination during the gas-phase deposition of the MIM electrode (BE) on the porous low-k film. A molecular-pore-stack (MPS) SiOCH film (k=2.5) with very small pores (0.4 nm-diameter) is found to be the best candidate for the CAPL structure, applicable to eDRAM with high performance logics for 28 nm-node and beyond. IntroductionEmbedded DRAM with a conventional COB (capacitor over bit-line) in SiO 2 pre-metal-dielectric (PMD) is attractive to keep high bandwidth, low latency, and low power of the memory-logic interface with small cell size [1-2]. The conventional COB structure, as shown in Fig. 1, is a straightforward solution to insert add-on process for MIM capacitors into the CMOS technology. In this structure, long W-contacts, what we call bypass contact (BCT), are needed to connect the transistors with Cu Metal-1 (Fig. 1). Scaling of the CMOS technology shrinks the diameter of the W-BCT and increases the aspect ratio of W-contact. These changes bring significant increases in parasitic resistance and capacitance of the long W-BCT (Fig. 2), and degrading circuit performances of CMOS logics with the eDRAM, compared to those of pure CMOS logics.To suppress those parasitic effects, a structural paradigm shift is needed in scaled-down eDRAM device,

Highly selective dry-etching processes are developed for conventional via-first (VF) pattering sequences to fabricate reliable Cu dual-damascene interconnects (DDI) in carbon-rich low-k films, such as a molecular-pore-stack (MPS) SiOCH film (k = 2.55). The carbon-rich MPS film, which had excellent endurance against plasma-processes, acted as etching stopper during hard-mask (HM)-etching on it, and the high selectivity of trench-HM etching reduced variability of over-etching depth in the MPS film. This effect reduced variability in trench-depth in the MPS film, or interconnect characteristics such as capacitance–resistance (C–R) time delay. The via yield and reliability were influenced also by via-etch selectivity of MPS against SiCN cap underlain. We found that the SiCN thickness remained after the via etch should be greater than 10 nm to prevent Cu from oxidation by O2 ashing step followed. Chemical-reaction-enhanced gas chemistry in N2–CF X –Ar system, i.e., high N2/Ar ratio under limited CF X supply, increased the etching selectivity of MPS to keep enough thickness of SiCN. Early-failure-mode in electro-migration test was suppressed by the high selective via-etch. Precise selectivity control for robust carbon-rich low-k films was very important to achieve the low variability and high reliability of scaled-down Cu interconnects.

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We estimate how well we will know the parameters of solar neutrino oscillations after KamLAND and Borexino. The expected error on ∆m 2 is few per-mille in the VO and QVO regions, few per-cent in the LMA region, and around 10% in the LOW region. The expected error on sin 2 2θ is around 5%. KamLAND and Borexino will tell unambiguously which specific new measurement, dedicated to pp solar neutrinos, is able to contribute to the determination of θ and perhaps of ∆m 2 . The present data suggest as more likely outcomes: no measurement, or the total pp rate, or its day/night variation.