International Business Machines Corporation

Samsung Electronics Co., Ltd.

Globalfoundries Inc.

Stmicroelectronics Gmbh

Gerald Leake, Jr

Terence B Hook

Ju Youn Kim

Pietro Montanini

Brett H Engel

Roderick Miller

Use of a replacement metal gate (RMG) process provides an opportunity to create precision polysilicon resistors alongside metal gate transistors. During formation of a sacrificial polysilicon gate, the precision polysilicon resistor can also be formed from the same polysilicon film. The polysilicon resistor can be slightly recessed so that a protective insulating layer can cover the resistor during subsequent replacement of the sacrificial gate with a metal gate. The final structure of the precision polysilicon resistor fabricated using such a process is more compact and less complex than existing structures that provide metal resistors for integrated circuits having metal gate transistors. Furthermore, the precision polysilicon resistor can be freely tuned to have a desired sheet resistance by either implanting the polysilicon film with dopants, adjusting the polysilicon film thickness, or both.

Precision polysilicon resistors

A first semiconductor region and a second semiconductor region separated by a shallow trench isolation region are formed in a semiconductor substrate. A photoresist is applied and patterned so that the first semiconductor region is exposed, while the second semiconductor region is covered. Depending on the setting of parameters for the location of an edge of the patterned photoresist, the slope of sidewalls of the photoresist, the thickness of the photoresist, and the direction of ion implantation, ions may, or may not, be implanted into the entirety of the surface portion of the first semiconductor region by shading or non-shading of the first semiconductor region. The semiconductor substrate may further comprise a third semiconductor region into which the dopants are implanted irrespective of the shading or non-shading of the first semiconductor region. The selection of shading or non-shading may be changed from substrate to substrate in manufacturing.

Method of selectively adjusting ion implantation dose on semiconductor devices

Growing community of inventors

Wallkill, NY, United States of America

Gerald Leake, Jr