Mask repair plays an important role in yielding advanced masks that support the lithography roadmap. It is also one of the more challenging parts of mask fabrication. Electron beam induced deposition and etching have shown great potential for mask repair applications. Our work has demonstrated that e-beam mask repair provides the superior resolution and damage-free process that is needed to support mask generations for the 32 nm technology node and beyond. This article describes an installed e-beam mask repair tool at Intel Mask Operation and discusses the capabilities of this enabling technology based on results obtained from repairing masks with "defects" intentionally inserted into the design ͑programmed defect masks͒. Specifically, results are presented for quartz etch repair of alternating phase shift masks and TaBN absorber etch of extreme ultraviolet masks, two of the most difficult types of mask to repair using conventional methods.

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Electron beam induced etching (EBIE) is an important technique for repairing nanoscale defects on extreme ultraviolet (EUV) lithography masks as it provides excellent spatial resolution and etch selectivity while minimizing collateral damage to the mask. While EBIE itself is a complex process, a current problem with EBIE of the TaN EUV mask absorber layer using XeF2 is the spontaneous etching of repaired features during subsequent edits of the mask. This work explores three passivation techniques for controlling the spontaneous etching after an EBIE repair is made. An oxygen plasma was used to attempt to oxidize the TaN sidewalls, but it was not successful at stopping the spontaneous etching. An active electron beam induced passivation using water was successful at stopping the spontaneous etching. Also, simple adsorption of water molecules on the TaN sidewalls was successful at inhibiting spontaneous etching. The successful passivation strategies are affected by subsequent scanning electron beam imaging. It was determined that the electron beam activated passivation can be damaged by electron beam imaging in the presence of residual XeF2 on the surface. Also, the adsorbed water passivation strategy is susceptible to electron induced desorption of the water.

As for the machine tool with high-speed ball screw feed system, the quite large friction force may change the real contact state of kinematic joints, which would further affect the dynamic characteristics of the whole system. In this article, an equivalent dynamic model of high-speed ball screw feed system was established using hybrid element method. The equivalent axial stiffness of individual kinematic joint and system transmission stiffness were all derived considering the influence of feed rate. The variation in the system natural frequency with feed rates was analyzed using the model proposed and also verified by experiments. The results show that the system natural frequency in motion state is larger than that in static state and behaves differently in different feed rates. The equivalent axial stiffness of the rear-end support bearing unit can reduce to 0 as the feed rate increases, which further leads to a critical value for system natural frequency. In the high-speed motion of the feed system, resonance may occur when the system natural frequency is almost same to the torque ripple harmonic frequency of the servo motor.