摘要:
This invention relates to a novel fuse structure and method for deleting redundant circuit elements on integrated circuits. This fuse structure is useful for increasing the repair yield on RAM chips by deleting defective rows of memory cells. The method involves forming a fuse area in a patterned electrically conducting layer also used to form interconnections. A relatively thin (0.4 um) insulating layer is deposited having a uniform thickness across the substrate. The next level of patterned interconnections is formed with a portion of the layer aligned over the fuse area to serve as an etch-stop layer. For example, the conducting layers can be the first and second poly-silicon layers on a RAM chip. The remaining multilevel of interconnections is then formed having a number of relatively thick interlevel dielectric (ILD) layers interposed which can have an accumulative large variation in thickness across the substrate. Fuse windows (openings) are then selectively etched in the ILD layers to the etch-stop layer and the etch-stop layer is selectively etched in the fuse window to the insulating layer over the fuse area. This process allows fuse structures to be built without overetching that can cause fuse damage. The uniform thick insulating layer allows repeatable and reliable laser abrading (evaporation) to open the desired fuses.
摘要:
This invention relates to a novel fuse structure and method for deleting redundant circuit elements on integrated circuits. This fuse structure is useful for increasing the repair yield on RAM chips by deleting defective rows of memory cells. The method involves forming a fuse area in a patterned electrically conducting layer also used to form interconnections. A relatively thin (0.4 um) insulating layer is deposited having a uniform thickness across the substrate. The next level of patterned interconnections is formed with a portion of the layer aligned over the fuse area to serve as an etch-stop layer. For example, the conducting layers can be the first and second polysilicon layers on a RAM chip. The remaining multilevel of interconnections is then formed having a number of relatively thick interlevel dielectric (ILD) layers interposed which can have an accumulative large variation in thickness across the substrate. Fuse windows (openings) are then selectively etched in the ILD layers to the etch-stop layer and the etch-stop layer is selectively etched in the fuse window to the insulating layer over the fuse area. This process allows fuse structures to be built without overetching that can cause fuse damage. The uniform thick insulating layer allows repeatable and reliable laser abrading (evaporation) to open the desired fuses.
摘要:
A new method for forming stacked capacitors for DRAMs having improved yields when the bottom electrode is misaligned to the node contact is achieved. A planar silicon oxide (SiO.sub.2) first insulating layer, a Si.sub.3 N.sub.4 etch-stop layer, and a disposable second insulating layer are deposited. First openings for node contacts are etched in the insulating layers. A polysilicon layer is deposited and etched back to form node contacts in the first openings. The node contacts are recessed in the second insulating layer, but above the etch-stop layer to form node contacts abutting the etch-stop layer. A disposable third SiO.sub.2 layer is deposited. Second openings for bottom electrodes are etched over and to the node contacts. A conformal second polysilicon layer is deposited and chem/mech polished back to form the bottom electrodes in the second openings. The third and second insulating layers are removed by wet etching to the etch-stop layer. When the second openings are misaligned over the node contact openings, the polysilicon plugs abutting the Si.sub.3 N.sub.4 etch-stop layer protect the SiO.sub.2 first insulating layer from being eroded over the devices on the substrate. The capacitors are completed by forming a thin dielectric layer on the bottom electrodes, and forming top electrodes from a patterned third polysilicon layer.
摘要翻译:实现了当底电极不对准节点接触时,用于形成具有提高的产量的DRAM的叠层电容器的新方法。 沉积平面氧化硅(SiO 2)第一绝缘层,Si 3 N 4蚀刻停止层和一次性第二绝缘层。 在绝缘层中蚀刻用于节点接触的第一开口。 沉积多晶硅层并回蚀刻以在第一开口中形成节点接触。 节点触点凹陷在第二绝缘层中,但在蚀刻停止层之上,以形成邻接蚀刻停止层的节点触点。 沉积一次性第三SiO 2层。 底部电极的第二个开口被蚀刻到节点触点上。 沉积保形的第二多晶硅层,并在第二开口中化学/机械抛光以形成底部电极。 第三绝缘层和第二绝缘层通过湿法蚀刻去除蚀刻停止层。 当第二开口在节点接触开口上不对准时,邻接Si 3 N 4蚀刻停止层的多晶硅栓保护SiO 2第一绝缘层免受衬底上的器件的侵蚀。 通过在底部电极上形成薄的电介质层,并从图案化的第三多晶硅层形成顶部电极来完成电容器。