Trench type field effect transistor and forming method thereof

• Main Authors: REN ZHIYUAN, SONG JINXING, LI YANXU
• Format: Patent
• Language: Chinese; English
• Published: 13.11.2020
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

The invention provides a trench type field effect transistor and a forming method thereof. A trench type terminal structure is arranged in a terminal region, and a second dielectric layer in the terminal structure is enabled to have a larger thickness, so as to improve the voltage endurance capability of the device, thereby facilitating the reduction of the size of the device. Moreover, the seconddielectric layer in the second trench closest to the boundary of the cellular region specifically comprises a thin layer part and a thick layer part, and the thin layer part can be simultaneously formed in combination with the preparation process of the first dielectric layer in the cellular region, so that the preparation process is simplified, and the height difference of the cellular region and the terminal region at the junction can be relieved. 本发明提供了一种沟槽型场效应晶体管及其形成方法。通过在终端区中设置沟槽型的终端结构，并使终端结构中的第二介质层具备较大的厚度，以提高器件的耐压能力，从而有利于实现器件尺寸的缩减。并且，针对最靠近元胞区的边界第二沟槽中的第二介质层而言其具体包括薄层部和厚层部，该薄层部可以结合元胞区中的第一介质层的制备工艺同时形成，不仅有利于简化制备工艺，并