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Tensile strength and elastic modulus measurements of low-pressure chemical vapour deposited (LPCVD) polysilicon films were performed on freestanding microtensile specimens (fibers) fabricated from the films. Various annealing treatments were employed to alter the polysilicon grain size. Fibers were fabricated from films with grain sizes of 50, 100, and 500 nm. The fiber cross sectional area was 3.3 mu m3 and the gauge section was 30 mu m long. The fibers failed in a brittle fashion with tensile strengths between 2.7 and 3.4 GPa. Fibers fabricated from polysilicon with 500 nm grain size had uniform equiaxial grains and were stronger than fibers made from smaller grain size material. This higher strength can be attributed to the better interface between the 500 nm grains as a result of the annealing process. The average elastic modulus of the fibers was 175 GPa.

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We evaluated atomic layer deposition (ALD) for the growth of HfO2 for integration in resistive RAM (ReRAM) test structures on 300mm wafers in order to optimize electrical performance for use as synaptic device elements in analog in-memory computing. The effect of ALD oxidant was evaluated and it was shown that H2O outperformed O3 in terms of better uniformity and lower forming voltage. By utilizing H-based plasma after deposition or inserted as an intermediate step during deposition, we were able to further decrease forming voltage for a fixed dielectric thickness. Reducing deposition temperature to 200°C in conjunction with the H-based plasma treatment resulted in additional reduction in forming voltage. Stable high-resistance switching with analog behavior in scaled BEOL devices was obtained using this HfO2-based ReRAM. Additionally, a tight distribution of forming voltage was obtained ensuring that 99.9999% of devices in a 14nm ReRAM module can be formed below the targeted voltage.