公开(公告)号：US6015734A

公开(公告)日：2000-01-18

申请号：US148561

申请日：1998-09-04

Applicant: Kuo Ching Huang ,  Yu Hua Lee ,  Cheng-Ming Wu

Inventor： Kuo Ching Huang ,  Yu Hua Lee ,  Cheng-Ming Wu

IPC: H01L21/8242 ,  H01L27/108

CPC classification number: H01L27/10852 ,  H01L27/10817

Abstract: 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.

Abstract translation: 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。