Abstract: A photo mask includes a plurality of device features, a first assist feature, and a second assist feature. The device features are in a patterning region of a device region. The first assist feature are in the patterning region and adjacent to the device features. The first assist feature is for correcting an optical proximity effect in a photolithography process. The second assist feature is in a non-patterning region of the device region. The second assist feature is a sub-resolution correction feature, and a first distance between the second assist feature and one of the device features closest to the second assist feature is greater than a second distance between adjacent two of the device features.

Abstract: A photo mask includes a plurality of device features, a first assist feature, and a second assist feature. The device features are in a patterning region of a device region. The first assist feature are in the patterning region and adjacent to the device features. The first assist feature is for correcting an optical proximity effect in a photolithography process. The second assist feature is in a non-patterning region of the device region. The second assist feature is a sub-resolution correction feature, and a first distance between the second assist feature and one of the device features closest to the second assist feature is greater than a second distance between adjacent two of the device features.

Abstract: A photo mask includes a plurality of device features, a first assist feature, and a second assist feature. The device features are in a patterning region of a device region. The first assist feature are in the patterning region and adjacent to the device features. The first assist feature is for correcting an optical proximity effect in a photolithography process. The second assist feature is in a non-patterning region of the device region. The second assist feature is a sub-resolution correction feature, and a first distance between the second assist feature and one of the device features closest to the second assist feature is greater than a second distance between adjacent two of the device features.

Abstract: A method for forming a semiconductor device structure is provided. The method includes forming a gate stack and a conductive layer over a semiconductor substrate. The method includes forming a negative photoresist layer to cover the gate stack and a first portion of the conductive layer over the isolation structure and expose a second portion of the conductive layer. The method includes forming a mask layer over the negative photoresist layer and the conductive layer. The mask layer has trenches over the second portion of the conductive layer and an edge portion of the negative photoresist layer, and a thickness of the edge portion decreases in a direction away from the gate stack.

Abstract: A method for forming a semiconductor device structure is provided. The method includes forming a gate stack and a conductive layer over a semiconductor substrate. The method includes forming a negative photoresist layer to cover the gate stack and a first portion of the conductive layer over the isolation structure and expose a second portion of the conductive layer. The method includes forming a mask layer over the negative photoresist layer and the conductive layer. The mask layer has trenches over the second portion of the conductive layer and an edge portion of the negative photoresist layer, and a thickness of the edge portion decreases in a direction away from the gate stack.

Abstract: A method for forming a semiconductor device structure is provided. The method includes forming a gate stack and a conductive layer over a semiconductor substrate. The semiconductor substrate has a first region and a second region isolated from each other by an isolation structure in the semiconductor substrate. The gate stack is formed over the first region. The method includes forming a negative photoresist layer over the first region and a first portion of the conductive layer over the isolation structure to cover the gate stack. The method includes forming a mask layer over the negative photoresist layer and the conductive layer. The mask layer has trenches over a second portion of the conductive layer. The method includes removing the second portion through the trenches. The method includes removing the mask layer. The method includes removing the negative photoresist layer.

Abstract: A method for forming a semiconductor device structure is provided. The method includes forming a gate stack and a conductive layer over a semiconductor substrate. The semiconductor substrate has a first region and a second region isolated from each other by an isolation structure in the semiconductor substrate. The gate stack is formed over the first region. The method includes forming a negative photoresist layer over the first region and a first portion of the conductive layer over the isolation structure to cover the gate stack. The method includes forming a mask layer over the negative photoresist layer and the conductive layer. The mask layer has trenches over a second portion of the conductive layer. The method includes removing the second portion through the trenches. The method includes removing the mask layer. The method includes removing the negative photoresist layer.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a semiconductor substrate. The semiconductor device structure includes a first gate stack over the semiconductor substrate. The first gate stack includes a first gate and a second gate over the first gate, and the first gate and the second gate are electrically isolated from each other. The semiconductor device structure includes a ring structure surrounding the first gate stack. The ring structure is made of a conductive material.

Abstract: A semiconductor device structure is provided. The semiconductor device structure includes a semiconductor substrate. The semiconductor device structure includes a first gate stack over the semiconductor substrate. The first gate stack includes a first gate and a second gate over the first gate, and the first gate and the second gate are electrically isolated from each other. The semiconductor device structure includes a ring structure surrounding the first gate stack. The ring structure is made of a conductive material.