Method of manufacturing a semiconductor device

Abstract

In a patterning process of a semiconductor device having inverted stagger type TFTs, a normal photolithography step using diazo naphthoquinone (DNQ)-Novolac resin based positive photo resist is applied, and a problem of the area dependency of the photo resist pattern side wall taper angle may occur. The problem is critical for the reason of influence on variation of an etching shape in a dry-etching step. The present invention has an object to solve the above problem. In a photolithography step, which is patterning step of a semiconductor device having inverted stagger type TFTs, by adjusting a pre-bake temperature or a PEB (post-exposure-bake) temperature, and positively performing evacuation of solvent in a state of a photo resist film, the volume contraction by evacuation of solvent at the post-bake is reduced, and the problem of the area dependency of the photo resist pattern side wall taper angle is solved, which is deformation due to the volume contraction.

1. A method of manufacturing a semiconductor device, said method comprises the steps of:
 forming a first conductive film on an insulating surface; 
 forming a first photo resist pattern on the first conductive film; 
 dry-etching the first conductive film to form a first pattern; 
 depositing a first insulating film on the first pattern; 
 depositing a first semiconductor film on the first insulating film; 
 depositing a one conductivity type second semiconductor film on the first semiconductor film; 
 depositing a second conductive film on the one conductivity type second semiconductor film; 
 forming a second photo resist pattern on the second conductive film; 
 dry-etching the first semiconductor film, the one conductivity type second semiconductor film, and the second conductive film to form a second pattern; 
 depositing a third conductive film on the second pattern; 
 forming a third photo resist pattern on the third conductive film; and 
 etching the third conductive film and the second pattern to form a third pattern, 
 each of the steps of forming the first, the second and the third photo resist patterns comprising the steps of.:
 coating a photo resist; 
 performing a pre-bake after coating the photo resist; 
 performing an exposure after performing the pre-bake; 
 performing a development after the exposure; and 
 performing a post-bake after the development, 
 
 wherein a pre-bake temperature is within ±10° C., relative to a post-bake temperature. 
 
     
     
       2. A method of manufacturing a semiconductor device having inverted stagger type thin-film transistors, said method comprises the steps of:
 depositing a first conductive film on an insulating surface; 
 forming a first photo resist pattern on the first conductive film; 
 dry-etching the first conductive film to form a gate electrode; 
 depositing a gate insulating film on the gate electrode; 
 depositing a first semiconductor film on the gate insulating film; 
 depositing a one conductivity type second semiconductor film on the first semiconductor film; 
 depositing a second conductive film on the one conductivity-type second semiconductor film; 
 forming a second photo resist pattern on the second conductive film; 
 dry-etching the first semiconductor film, the one conductivity type second semiconductor film and the second conductive film to form a laminated film comprising the first semiconductor film, the one conductivity type second semiconductor film and the second conductive film; 
 depositing a third conductive film on the laminated film pattern; 
 forming a third photo resist pattern on the third conductive film; 
 etching the third conductive film to form a pixel electrode; and 
 dry-etching the laminated film to form a channel region from the first semiconductor film, to form a source region and a drain region from the one conductivity type second semiconductor film and to form a source electrode and a drain electrode from the second conductive film, 
 each of the steps of forming the first, the second and the third photo resist patterns comprising the steps of.:
 coating a photo resist; 
 performing a pre-bake after coating the photo resist; 
 performing an exposure after performing the pre-bake; 
 performing a development after performing the exposure; and 
 performing a post-bake after performing the development, 
 
 wherein a pre-bake temperature is within ±10° C. relative to a post-bake temperature. 
 
     
     
       3. A method of manufacturing, a semiconductor device according, to  claim 1 , wherein the step of performing, the exposure comprises performing an exposure using a multi-wavelength light. 
     
     
       4. A method of manufacturing a semiconductor device according to  claim 1 , wherein the step of performing the exposure comprises performing an exposure using an equivalent projection exposure apparatus. 
     
     
       5. A method of manufacturing a semiconductor device, said method comprises the steps of:
 depositing a first conductive film on an insulating surface; 
 forming a first photo resist pattern on the first conductive film; 
 dry-etching the first conductive film to form a first pattern; 
 depositing a first insulating film on the first pattern; 
 depositing a first semiconductor film on the insulating the insulating film; 
 depositing a one conductivity type second semiconductor film on the first semiconductor film; 
 depositing a second conductive film on the one conductivity type second semiconductor film; 
 forming a second photo resist pattern on the second conductive film; 
 dry-etching the first semiconductor film, the one conductivity type second semiconductor film, and the second conductive film to form a second pattern; 
 depositing a third conductive film on the second pattern; 
 forming a third photo resist pattern on the third conductive film; and 
 etching the third conductive film and the second pattern to form a third pattern, 
 each of the steps of forming the first, the second and the third photo resist patterns comprising the steps of:
 coating a photo resist; 
 performing a pre-bake after coating the photo resist; 
 performing an exposure after performing the pre-bake; 
 performing a post-exposure bake after performing the exposure; 
 performing a development after performing the post-exposure bake; and 
 performing a post-bake after performing the development, 
 
 wherein a post-exposure bake temperature is equal to or greater than a post-bake temperature. 
 
     
     
       6. A method of manufacturing a semiconductor device having inverted stagger type thin-film transistors,
 said method comprises the steps of: 
 depositing a first conductive film on an insulating surface; 
 forming a first photo resist pattern on the first conductive film; 
 dry-etching the first conductive film to form a gate electrode; 
 depositing a gate insulating film on the gate electrode; 
 depositing a first semiconductor film on the gate insulating film; 
 depositing a one conductivity type second semiconductor film on the first semiconductor film; 
 depositing a second conductive film on the one conductivity type second semiconductor film; 
 forming a second photo resist pattern on the second conductive film; 
 dry-etching the first semiconductor film, the one conductivity type second semiconductor film and the second conductive film to form a laminated film comprising the first semiconductor film, the one conductivity type second semiconductor film and the second conductive film; 
 depositing a third conductive film on the laminated film; 
 forming a third photo resist pattern on the third conductive film; 
 etching the third conductive film to form a pixel electrode; and 
 dry-etching the laminated film to form a channel region from the first semiconductor film, to form a source region and a drain region from the one conductivity type second semiconductor film and to form a source electrode and a drain electrode from the second conductive film, 
 each of the steps of forming the first, the second and the third photo resist patterns comprising the steps of;:
 coating a photo resist; 
 performing a pre-bake after coating the photo resist; 
 performing an exposure after performing the pre-bake; 
 performing a post-exposure bake after performing the exposure; 
 performing a development after performing the post-exposure; and 
 performing a post-bake after performing the development, 
 
 wherein a post-exposure bake temperature is equal to or higher than a post-bake temperature. 
 
     
     
       7. A method of manufacturing a semiconductor device according to  claim 5 , wherein the step of performing the exposure comprises performing an exposure using a single-wavelength light. 
     
     
       8. A method of manufacturing a semiconductor device according to  claim 5 , wherein the step of performing the exposure comprises performing an exposure using a reduction projection exposure apparatus. 
     
     
       9. A method of manufacturing a semiconductor device according to  claim 2 , wherein the step of performing the exposure comprises performing an exposure using a multi-wavelength light. 
     
     
       10. A method of manufacturing a semiconductor device according to  claim 2 , wherein the step of performing the exposure comprises performing an exposure using an equivalent projection exposure apparatus. 
     
     
       11. A method of manufacturing a semiconductor device according to  claim 6 , wherein the step of performing the exposure comprises performing an exposure using a single-wavelength light. 
     
     
       12. A method of manufacturing a semiconductor device according to  claim 6 , wherein the step of performing the exposure comprises performing an exposure using a reduction projection exposure apparatus. 
     
     
       13. A method of manufacturing a semiconductor device, said method comprising the steps of:
 forming a conductive film on an insulating surface;   forming a photo resist on the conductive film;   pre-baking the photo resist at a first temperature;   performing an exposure to the photo resist after pre-baking the photo resist;   performing a development after the exposure;   post-baking the photo resist at a second temperature after the development; and   etching the conductive film by using the post-baked photo resist to form a wiring having a taper portion,   wherein the first temperature is within ±10° C. relative to the second temperature.   
     
     
       14. A method of manufacturing a semiconductor device according to claim 13, wherein the step of performing the exposure comprises performing an exposure using a multi-wavelength light. 
     
     
       15. A method of manufacturing a semiconductor device according to claim 13, wherein the step of performing the exposure comprises performing an exposure using an equivalent projection exposure apparatus. 
     
     
       16. A method of manufacturing a semiconductor device, said method comprising the steps of:
 forming a conductive film on an insulating surface;   coating a photo resist on the conductive film;   pre-baking the photo resist at a first temperature;   performing an exposure to the pre-baked photo resist;   performing a post-exposure bake to the photo resist at a second temperature;   performing a development to the post-exposure baked photo resist;   post-baking the developed photo resist at a third temperature; and   etching the conductive film by using the post-baked photo resist to form a wiring having a taper portion,   wherein the second temperature is equal to or greater than the third temperature.   
     
     
       17. A method of manufacturing a semiconductor device according to claim 16, wherein the step of performing the exposure comprises performing an exposure using a single-wavelength light. 
     
     
       18. A method of manufacturing a semiconductor device according to claim 16, wherein the step of performing the exposure comprises performing an exposure using a reduction projection exposure apparatus.