公开(公告)号：US20030170964A1

公开(公告)日：2003-09-11

申请号：US10385132

申请日：2003-03-10

Applicant: Micron Technology, Inc.

Inventor： David Y. Kao ,  Fernando Gonzalez

IPC: H01L021/76

CPC classification number: H01L21/76235 ,  H01L21/76202 ,  H01L21/76237

Abstract: An improved LOCOS method for forming a patterned silicon dioxide field region on a substrate assembly by implanting silicon ions into a silicon substrate. The implanted silicon ions partially randomize the lattice structure of the monocrystalline silicon in the silicon substrate and increase the availability of silicon to ambient oxygen, thus increasing the rate of oxidation of the silicon substrate. The implantation of the silicon substrate with silicon ions makes oxidation faster and reduces the formation of bird's beak structures, as compared to an unimplanted silicon substrate. The method may also incorporate a nitride spacer formed at a periphery of an opening in the silicon nitride hard mask. The nitride spacer decreases straggle and the dimension of the resultant silicon dioxide field region, such that the dimensions thereof are below photolithography resolution limits. An improved shallow trench isolation region is also taught and reduces cross-talk and allows active regions to be formed closer together. The improved shallow trench isolation region is formed with a method that includes implanting silicon ions into an isolation trench followed by formation of a thermal oxide in the isolation trench that has greater lateral dimensions at the bottom of the isolation trench than at the top. A layer of silicon nitride is deposited to fill the remainder of the isolation trench and form the shallow trench isolation region.

Abstract translation: 一种用于通过将硅离子注入到硅衬底中在衬底组件上形成图案化二氧化硅场区的改进的LOCOS方法。 注入的硅离子部分地使硅衬底中的单晶硅的晶格结构随机化，并增加了硅对环境氧的可用性，从而提高了硅衬底的氧化速率。 与未植入的硅衬底相比，用硅离子注入硅衬底使氧化更快并且减少了鸟的喙结构的形成。 该方法还可以包括形成在氮化硅硬掩模中的开口的周边处的氮化物间隔物。 氮化物间隔物减小了所得二氧化硅场区的分布和尺寸，使得其尺寸低于光刻分辨率极限。 还教导了改进的浅沟槽隔离区域并减少了串扰，并且允许有源区域更靠近地形成。 改进的浅沟槽隔离区域由一种方法形成，该方法包括将硅离子注入到隔离沟槽中，随后在隔离沟槽中形成热氧化物，该隔离沟槽在隔离沟槽的底部具有比顶部更大的横向尺寸。 沉积氮化硅层以填充隔离沟槽的其余部分并形成浅沟槽隔离区域。