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A TFT is manufactured using at least five photomasks in a conventional liquid crystal display device, and therefore the manufacturing cost is high. By performing the formation of the pixel electrode 119, the source region 115 and the drain region 116 by using three photomasks in three photolithograp

A TFT is manufactured using at least five photomasks in a conventional liquid crystal display device, and therefore the manufacturing cost is high. By performing the formation of the pixel electrode 119, the source region 115 and the drain region 116 by using three photomasks in three photolithography steps, a liquid crystal display device prepared with a pixel TFT portion, having a reverse stagger type n-channel TFT, and a storage capacitor can be realized.

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What is claimed is: 1. A method of manufacturing a semiconductor device comprising: a first step of forming a gate wiring and a plurality of convex portions in a pixel portion by using a first mask; a second step of forming an insulating film covering said gate wiring and said plurality of convex

What is claimed is: 1. A method of manufacturing a semiconductor device comprising: a first step of forming a gate wiring and a plurality of convex portions in a pixel portion by using a first mask; a second step of forming an insulating film covering said gate wiring and said plurality of convex portions; a third step of forming a first amorphous semiconductor film on said insulating film; a fourth step of forming a second amorphous semiconductor film, containing an impurity element which imparts n-type conductivity, on said first amorphous semiconductor film; a fifth step of forming a first conductive film on said second amorphous semiconductor film; a sixth step of forming a second mask on the first conductive film; a seventh step of sequentially patterning said first conductive film, said second amorphous semiconductor film and said first amorphous semiconductor film, by using the second mask; thereby forming a wiring from said first conductive film; an eighth step of forming a second conductive film contacting and overlapping said wiring; a ninth step of patterning said second conductive film, said wiring, said second amorphous semiconductor film and a portion of said first amorphous semiconductor film, by using a third mask, sequentially, thereby forming a pixel electrode made from said second conductive film, a source wiring and a drain electrode made from said wiring, and a source region and a drain region made from the second amorphous semiconductor film. 2. The method of manufacturing a semiconductor device as claimed in claim 1, wherein said gate wiring and said plurality of convex portions are of the same material. 3. The method of manufacturing a semiconductor device as claimed in claim 1, wherein said insulating film is formed on a substrate on which said plurality of convex portions are formed, and has an uneven surface. 4. The method of manufacturing a semiconductor device as claimed in claim 1 wherein said pixel electrode is formed on an insulating film on which unevenness is formed, and has an uneven surface. 5. The method of manufacturing a semiconductor device as claimed in claim 1, wherein said first step of forming said gate wiring, said plurality of convex portions and a capacitor wiring by using said first mask is performed at the same time. 6. A method of manufacturing a semiconductor device comprising: a first step of forming a gate wiring and a capacitor wiring by using a first mask; a second step of forming an insulating film covering said gate wiring and said capacitor wiring; a third step of forming a first amorphous semiconductor film on said insulating film; a fourth step of forming a second amorphous semiconductor film, containing an impurity element which imparts n-type conductivity, on said first amorphous semiconductor film; a fifth step of forming a first conductive film on said second amorphous semiconductor film; a sixth step of forming a second mask on the first conductive film; a seventh step of sequentially patterning said first conductive film, said second amorphous semiconductor film, and said first amorphous semiconductor film, by using the second mask, thereby forming a first wiring and a second wiring made from said first conductive film; forming a third amorphous semiconductor film and a fourth amorphous semiconductor film made from said first amorphous semiconductor film and forming a fifth amorphous semiconductor film and a sixth amorphous semiconductor film made from said second amorphous semiconductor film; an eighth step of forming a second conductive film contacting and overlapping said first wiring and said second wiring; and a ninth step of patterning said second conductive film, said first wiring, and said fifth amorphous semiconductor film by using a third mask, sequentially, thereby forming a pixel electrode made from said second conductive film, a source wiring and a drain electrode made from said first wiring, and a source region and a drain region made from the fifth amorphous semiconductor film, wherein said pixel electrode, said second wiring, said fourth amorphous semiconductor film and said sixth amorphous semiconductor film overlap said capacitor wiring. 7. The method of manufacturing a semiconductor device as claimed in any one of claims 1 or 6, wherein said insulating film is formed by sputtering. 8. The method of manufacturing a semiconductor device as claimed in any one of claims 1 or 6, wherein said first amorphous semiconductor film is formed by sputtering. 9. The method of manufacturing a semiconductor device as claimed in any one of claims 1 or 6, wherein said second amorphous semiconductor film is formed by sputtering. 10. The method of manufacturing a semiconductor device as claimed in any one of claims 1 or 6, wherein said second step to said fifth step are performed in succession within the same chamber. 11. The method of manufacturing a semiconductor device as claimed in any one of claims 1 or 6, wherein said insulating film is formed by plasma CVD. 12. The method of manufacturing a semiconductor device as claimed in any one of claims 1 or 6, wherein said first amorphous semiconductor film is formed by plasma CVD. 13. The method of manufacturing a semiconductor device as claimed in claim 1 or 6 wherein said second amorphous semiconductor film is formed by plasma CVD. 14. The method of manufacturing a semiconductor device as claimed in any one of claims 1 or 6, wherein said second conductive film is a transparent conductive film. 15. A method of manufacturing a semiconductor device comprising: a first step of forming a gate wiring, a terminal and a capacitor wiring by using a first mask; a second step of forming an insulating film covering said gate wiring, said terminal and said capacitor wiring; a third step of forming a first amorphous semiconductor film on said insulating film; a fourth step of forming a second amorphous semiconductor film, containing an impurity element which imparts n-type conductivity, on said first amorphous semiconductor film; a fifth step of forming a first conductive film on said second amorphous semiconductor film; a sixth step of patterning said first amorphous semiconductor film, said second amorphous semiconductor film, and said first conductive film by using a second mask, thereby forming a wiring made from said first conductive film; a seventh step of patterning said insulating film on said terminal by using a third mask; an eight step of forming a second conductive film contacting and overlapping said wiring and an upper surface and a side surface of said terminal; and a ninth step of patterning said second conductive film, said wiring, and said second amorphous semiconductor film by using a fourth mask, thereby forming a pixel electrode and a third conductive film made from said second conductive film, a source wiring and a drain electrode made from said wiring, and a source region and a drain region made from said second amorphous semiconductor film. 16. The method of manufacturing a semiconductor device according to claim 15, wherein said gate wiring, said terminal and said capacitor wiring are of the same material. 17. The method of manufacturing a semiconductor device according to claim 15, wherein the second conductive film is a transparent conductive film.