公开(公告)号：US09202701B1

公开(公告)日：2015-12-01

申请号：US14572805

申请日：2014-12-17

Applicant: UNITED MICROELECTRONICS CORP.

Inventor： Kun-I Chou ,  Chi-Cheng Huang ,  Yu-Chun Chang ,  Ling-Hsiu Chou ,  Tseng-Fang Dai ,  Jheng-Jie Huang ,  Ping-Chia Shih

IPC: H01L21/336 ,  H01L21/28 ,  H01L27/115

CPC classification number: H01L21/28282 ,  H01L29/66833 ,  H01L29/792

Abstract: A method for manufacturing a silicon-oxide-nitride-oxide-silicon non-volatile memory cell includes following steps. An implant region is formed in a substrate. A first oxide layer, a nitride layer, and a second oxide layer are formed and stacked on the substrate. A density of the second oxide layer is higher than a density of the first oxide layer. A first photoresist pattern is formed on the second oxide layer and corresponding to the implant region. A first wet etching process is then performed to form an oxide hard mask. A second wet etching process is performed to remove the nitride layer exposed by the oxide hard mask to form a nitride pattern. A cleaning process is then performed to remove the oxide hard mask and the first oxide layer exposed by the nitride pattern, and a gate oxide layer is then formed on the nitride pattern.

Abstract translation: 一种用于制造氧化硅 - 氮化物 - 氧化物 - 硅非易失性存储单元的方法包括以下步骤。 在衬底中形成植入区域。 形成第一氧化物层，氮化物层和第二氧化物层并堆叠在基板上。 第二氧化物层的密度高于第一氧化物层的密度。 第一光致抗蚀剂图案形成在第二氧化物层上并对应于植入区域。 然后进行第一湿法蚀刻工艺以形成氧​​化物硬掩模。 执行第二湿法蚀刻工艺以去除由氧化物硬掩模暴露的氮化物层以形成氮化物图案。 然后进行清洁处理以除去由氮化物图案暴露的氧化物硬掩模和第一氧化物层，然后在氮化物图案上形成栅极氧化物层。