Method of forming a display device by using separate masks in forming source and drain regions of mos transistors

Abstract

A method of forming a display device is provided. The method includes the following steps: providing a substrate which includes a driving circuit region and a pixel region; forming a first island and a second island in the driving circuit region on the substrate with a semiconductor material; performing a first ion implantation process to dope ions into both of the first island and the second island; forming a first patterned mask on the substrate to cover the second island and expose a part of the first island; performing a second ion implantation process by using the first patterned mask as a mask to form a first source/drain region in the first island; removing the first patterned mask; forming a first gate and a second gate on the first island and the second island respectively; forming a second patterned mask on the substrate to cover the first island and expose a part of the second island; and performing a third ion implantation process by using both of the second patterned mask and the second gate as a mask to form a second source/drain region in the second island. The first island, the first source/drain region, and the first gate form a NMOS device, and the second island, the second source/drain region, and the second gate form a PMOS device.

1 . An electronic device, comprising:
 a display device and an input unit coupled to the display device for controlling display of the display device,
 wherein the display device is formed by the following steps:
 providing a substrate having a driving circuit region and a pixel region; 
 
 forming a first island and a second island in the driving circuit region on the substrate with a semiconductor material; 
 performing a first ion implantation process to dope ions into both of the first island and the second island; 
 forming a first patterned mask on the substrate to fully cover the second island and expose a part of the first island after performing the first ion implantation process; 
 performing a second ion implantation process by using the first patterned mask as a mask to form a first source/drain region in the first island;
 removing the first patterned mask; 
 
 forming a first gate and a second gate on the first island and the second island respectively after the first and second ion implantation processes have been performed; 
 forming a second patterned mask on the substrate to cover the first island and expose a part of the second island; and 
 performing a third ion implantation process by using both of the second patterned mask and the second gate as a mask to form a second source/drain region in the second island; 
 wherein the first island, the first source/drain region, and the first gate form a NMOS device, and the second island, the second source/drain region, and the second gate form a PMOS device. 
   
     
     
         2 . The electronic device according to  claim 1 , a threshold voltage of the NMOS device is about between 0.5V and 1V, and a threshold voltage of the PMOS device is about between −0.5V and −1V. 
     
     
         3 . The electronic device according to  claim 1 , wherein a third island in the pixel region is formed by the step of forming the first and the second islands; wherein a pixel source/drain region and a lower electrode in the third island is formed by the step of forming the first source/drain region; and wherein a pixel electrode and an upper electrode on the third island is formed by the step of forming the first and the second gates. 
     
     
         4 . The electronic device according to  claim 1 , wherein the display device comprises a liquid crystal display, an organic light emitting diode display (OLED), a plasma display, or an organic electro-luminescence display (OELD). 
     
     
         5 . The electronic device according to  claim 1 , wherein the electronic device is a mobile phone, a digital camera, a personal digital assistant (PDA), a notebook, a desktop computer, a television, a car display, an aerial display, a digital photo frame, a global positioning system, or a portable DVD player.