Ultra-thin chips (UTCs) are needed to meet the performance and packaging related requirements of flexible electronics and 3D integrated circuits (ICs). However, handling of UTCs (<50 μm thick), particularly after thinning, is a challenging task as the excessive mechanical stresses could lead to cracking. Such damages could be prevented by restricting the stresses to acceptable levels. Herein, we present a new reliable and cost-effective method based on a polymethylmethacrylate (PMMA) sacrificial layer (20 μm-thick). The PMMA layer results in 4 order of magnitude lower stress on UTCs and, as a result, the reliable removal or debonding of UTCs (35 μm-thick) from the glass substrate has been achieved. The distinctive features of the presented method are high reliability and cost-effectiveness (an order of magnitude cheaper) with respect to conventional methods that use UV curable tapes. The UTCs with metal-oxide-semiconductor capacitors (MOSCAPs) devices were also obtained using this approach and were evaluated under different bending conditions. The stable and uniform performance (134 pF) observed under bending conditions demonstrates that the presented technique could be useful for integration of high-performance flexible UTCs on flexible printed circuit boards for various practical application.

需要超薄芯片 (UTC) 来满足柔性电子和 3D 集成电路 (IC) 的性能和封装相关要求。然而，处理 UTC（<50 μm 厚），特别是在减薄之后，是一项具有挑战性的任务，因为过度的机械应力可能导致开裂。可以通过将应力限制在可接受的水平来防止这种损坏。在此，我们提出了一种基于聚甲基丙烯酸甲酯 (PMMA) 牺牲层（20 μm 厚）的可靠且经济高效的新方法。PMMA 层使 UTC 上的应力降低了 4 个数量级，因此，已经实现了 UTC（35 微米厚）从玻璃基板上的可靠去除或剥离。与使用紫外线固化胶带的传统方法相比，所提出方法的显着特点是高可靠性和成本效益（便宜一个数量级）。还使用这种方法获得了带有金属氧化物半导体电容器 (MOSCAP) 器件的 UTC，并在不同的弯曲条件下进行了评估。在弯曲条件下观察到的稳定和均匀的性能 (1​​34 pF) 表明，所提出的技术可用于将高性能柔性 UTC 集成到柔性印刷电路板上以用于各种实际应用。