Claims
- 1. A method of manufacturing a semiconductor device having an ESD protection element, comprising the steps of:(a) preparing a semiconductor substrate of a first conductivity type mainly composed of a first material; (b) selectively forming a semiconductor region for ESD protection including a second material that extends a first depth from a surface of said semiconductor substrate, said second material having a smaller breakdown field than said first material; and (c) forming first and second semiconductor regions of a second conductivity type independently of each other in a surface of said semiconductor substrate so that no contiguous portion of the first and second semiconductor regions extend as deep or deeper than said first depth from the surface of the semiconductor substrate in order that first and second edge portions of the first and second semiconductor regions are formed opposed to each other and fully in said semiconductor region for ESD protection in the manufactured semiconductor device.
- 2. The method of claim 1 wherein, said selectively forming step (b) includes conducting an ion implantation of the second material in the upper portion of said semiconductor substrate, to form said semiconductor region for ESD protection as a mixture of said second material and said first material.
- 3. The method of claim 1 wherein,said second material contains a mixture of said first material and a specific material having the smaller breakdown field than said first material; and said selectively forming step (b) includes the steps of: (b-1) forming a groove in an upper portion of said semiconductor substrate; and (b-2) forming said semiconductor region for ESD protection in said groove by an epitaxial growth of said second material from said semiconductor substrate extending around said groove.
- 4. The method of claim 1 wherein said first material contains silicon (Si) and said second material includes germanium (Ge).
- 5. The method of claim 1 wherein said forming step (c) includes the steps of:(c-1) selectively forming an insulating film on said semiconductor substrate; (c-2) forming a gate electrode on said insulating film; and (c-3) forming said first and second semiconductor regions using a mask portion including said gate electrode.
- 6. The method of claim 1 further comprising step (d), performed after step (a) and before step (b) that includes forming an isolated insulating film, with a portion that projects from said semiconductor substrate, and with a portion that is buried in a surface of said semiconductor substrate, wherein,said forming step (c) includes forming said first and second semiconductor regions using said isolated insulating film or a mask.
- 7. A method of manufacturing a semiconductor device, comprising the steps of:(a) preparing a semiconductor substrate of a first conductivity type mainly composed of a first material; (b) selectively forming a mask portion on said semiconductor substrate; (c) conducting an oblique ion implantation of a specific material having a smaller breakdown field than said first material from above said semiconductor substrate using said mask portion as a mask so as to form first and second partial semiconductor regions including said specific material for providing ESD protection spaced from each other so as to sandwich a non ESD region underlying said mask region; and (d) conducting a vertical ion implantation of an impurity of a second conductivity type from above said semiconductor substrate using said mask portion as a mask to form first and second semiconductor regions, said first semiconductor region having a first edge portion formed in complete engagement with said first partial semiconductor region for ESD protection and said second edge portion formed in complete engagement with said second partial semiconductor region for ESD protection in the manufactured semiconductor device.
- 8. The method of claim 7 wherein,said selectively forming step (b) includes the steps of: (b-1) selectively forming an insulating film on said semiconductor substrate; and (b-2) forming a gate electrode on said insulating film so that said mask portion includes said insulated film and said gate electrode.
- 9. A method of manufacturing a semiconductor device, comprising the steps of:(a) preparing a semiconductor substrate of a first conductivity type mainly composed of a first material; forming a groove in an upper portion of said semiconductor substrate; (c) forming a preliminary semiconductor region mainly including a mixture of said first material and a second material having a smaller breakdown field than said first material along an inner periphery of said groove by an epitaxial growth of said mixture from said semiconductor substrate extending around said groove; and (d) forming a partial semiconductor region for ESD protection mainly composed of said second material in said groove including said preliminary semiconductor region by an epitaxial growth of said second material from said preliminary semiconductor region.
- 10. The method of claim 9 wherein said first material includes silicon (Si), said second material includes germanium (Ge), and said mixture includes silicon germanium (SiGe).
Priority Claims (1)
Number |
Date |
Country |
Kind |
P10-009592 |
Jan 1998 |
JP |
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Parent Case Info
This application is a Division of application Ser. No. 09/092,019 filed on Jun. 05, 1998.
US Referenced Citations (21)
Foreign Referenced Citations (1)
Number |
Date |
Country |
4-34942 |
Feb 1992 |
JP |