Method of selectively adjusting ion implantation dose on semiconductor devices

A method of implanting ions into semiconductor substrates comprising:

• providing a first semiconductor substrate including a first semiconductor region and a second semiconductor region separated from each other by a first shallow trench isolation (STI) region;
• applying a first photoresist having a first thickness and a first resist sidewall slove angle to said first semiconductor substrate;
• patterning said first photoresist with a first pattern employing a lithographic mask, wherein said patterned first photoresist covers said second semiconductor region and extends from an edge of said second semiconductor region by a first overlap distance and does not cover any of said first semiconductor region;
• implanting first ions into said first semiconductor substrate in a first direction at a first non-zero tilt angle from a first surface normal of said first semiconductor substrate, wherein an entirety of said first semiconductor region and an entirety of said second semiconductor region are shielded from said first ions by said first patterned photoresist;
• providing a second semiconductor substrate including a third semiconductor region that has a same shape as said first semiconductor region and a fourth semiconductor region that has a same shape as said second semiconductor region, wherein said third and fourth semiconductor regions are separated from each other by a second shallow trench isolation (STI) region, wherein said second semiconductor substrate is a different from said first semiconductor substrate;
• applying a second photoresist having a second thickness and a second resist sidewall slope angle to said second semiconductor substrate;
• patterning said second photoresist with a second pattern employing said lithographic mask, wherein said patterned second photoresist covers said fourth semiconductor region and extends from an edge of said fourth semiconductor region by a second overlap distance and does not cover any of said third semiconductor region, and wherein said first pattern and said second pattern are the same;
• and
• implanting second ions into said second semiconductor substrate in a second direction at a second non-zero tilt angle from a second surface normal of said second semiconductor substrate, wherein an entirety of said third semiconductor region is shielded from said second ions by said second patterned photoresist, and wherein said second ions are implanted to an entirety of a surface portion of said fourth semiconductor region by setting said second thickness differently from said first thickness, by setting said second overlap distance differently from said first overlap distance, by setting said second non-zero tilt angle differently from said first non-zero tilt angle, by setting said second resist sidewall slope angle differently from said first resist sidewall slope angle, or a combination thereof.

A method of implanting ions into a semiconductor substrate comprising:

• providing a semiconductor substrate including a first semiconductor region, a second semiconductor region, and a third semiconductor region, wherein said second semiconductor region is separated from said first semiconductor region by a first shallow trench isolation (STI) region and said third semiconductor region is separated from said first semiconductor region by a second shallow trench isolation (STI) region;
• forming a patterned photoresist covering said second semiconductor region and not covering any of said first semiconductor region or said third semiconductor region;
• and
• implanting ions into said semiconductor substrate in a first direction at a first non-zero tilt angle from a surface normal of said semiconductor substrate, wherein said first direction is within an x-z plane of a Cartesian coordinate system having a z-axis along said surface normal, and an entirety of said first semiconductor region and an entirety of said second semiconductor region are shielded from said ions by said patterned photoresist, and wherein said ions are implanted to an entirety of a surface portion of said third semiconductor region;
• and
• implanting additional ions into said first semiconductor substrate in a second direction at a second non-zero tilt angle from said surface normal of said semiconductor substrate and with said patterned photoresist on said semiconductor substrate, wherein said second direction is within said x-z plane of said Cartesian coordinate system, said first direction and said second direction are different, and said entirety of said second semiconductor region is shielded from said additional ions by said patterned photoresist, and wherein said additional ions are implanted to an entirety of a surface portion of said first semiconductor region and to said entirety of said surface portion of said third semiconductor region.