Large angle ion implantation method

Claim 2

A large angle ion implanting method for forming amorphous layers in a semiconductor substrate comprising: a step of forming a mask pattern on said semiconductor substrate, said mask pattern having apertures for forming said amorphous layers; and a step of rotational implanting ions into said semiconductor substrate through said apertures of said mask pattern at a large implant angle equal to twenty degrees or more, when measured from a vertical line, with a dose amount necessary for forming said amorphous layers in said semiconductor layer and, thereby, forming each of said amorphous layers so as to have a substantially inverse trapezoidal vertical cross section each end of which is located beneath an edge of said mask pattern defining an aperture thereof.

Claim 3

The large angle ion implanting method as claimed in claim 1 wherein said semiconductor substrate is a silicon substrate.

Claim 4

The large angle ion implanting method as claimed in claim 2 wherein said implanting ions are arsenic ions.

Claim 5

A large angle ion implanting method for forming amorphous layers in a semiconductor substrate comprising: a step of forming a mask pattern on a silicon substrate as said semiconductor substrate, said mask pattern having apertures for forming said amorphous layers; and a step of rotational implanting ions into said silicon substrate through said apertures of said mask pattern at a large implant angle equal to twenty degrees or more, when measured from a vertical line, with a dose amount necessary for forming said amorphous layers in said silicon substrate and, thereby, forming each of said amorphous layers so as to have a substantially inverse trapezoidal vertical cross section each end of which is located beneath an edge of said mask pattern defining an aperture thereof, wherein said implanting ions are ions electrically inactive in said silicon substrate.

Claim 6

A large angle ion implanting method for forming amorphous layers in a semiconductor substrate comprising: a step of forming a mask pattern on a silicon substrate as said semiconductor substrate, said mask pattern having apertures for forming said amorphous layers; and a step of rotational implanting ions into said silicon substrate through said apertures of said mask pattern at a large implant angle equal to twenty degrees or more, when measured from a vertical line, with a dose amount necessary for forming said amorphous layers in said silicon substrate and, thereby, forming each of said amorphous layers so as to have a substantially inverse trapezoidal vertical cross section each end of which is located beneath an edge of said mask pattern defining an aperture thereof, wherein said implanting ions are ions electrically inactive in said silicon substrate.

Claim 7

The large angle ion implanting method as claimed in claim 4 wherein said ions electrically inactive in said silicon substrate are selected from the group consisting of silicon ion, germanium ion, argon ion, nitrogen ion, fluorine ion and molecular ion containing these ions.

Claim 8

The large angle ion implanting method as claimed in claim 5 wherein said ion implanting is carried out while maintaining said silicon substrate at a low temperature which is sufficiently low to form said amorphous layers at a lower dose of said implanting ions than when a higher temperature is employed.

Claim 9

The large angle ion implanting method for forming amorphous layers in a semiconductor substrate comprising: a step of forming a mask pattern on said semiconductor substrate, said mask pattern having apertures for forming said amorphous layers; a step of implanting ions electrically inactive in said semiconductor substrate through said apertures of said mask pattern at a large implant angle equal to twenty degrees or more to form first amorphous layers; and a step of implanting ions electrically active in said semiconductor substrate through said apertures of said mask pattern whereby second amorphous layers overlapping said first amorphous layers partially and impurity layers surrounding said first and second amorphous layers from the underside are formed.

Claim 10

The large angle ion implanting method for forming amorphous layers in a semiconductor substrate comprising: a step of forming a mask pattern on said semiconductor substrate, said mask pattern having apertures for forming said amorphous layers; a step of implanting ions electrically inactive in said semiconductor substrate through said apertures of said mask pattern at a large implant angle equal to twenty degrees or more to form first amorphous layers; and a step of implanting ions electrically active in said semiconductor substrate through said apertures of said mask pattern whereby second amorphous layers overlapping said first amorphous layers partially and impurity layers surrounding said first and second amorphous layers from the underside are formed.

Claim 11

The large angle ion implanting method as claimed in claim 7 wherein said step of implanting ions electrically active is comprised of a first step of implanting ions electrically active at a small angle ,and a second step of implanting ions electrically active at an angle larger than said small angle.

Claim 12

The large angle ion implanting method as claimed in claim 1, wherein said ion implanting method is applied to the formation of source-drain regions of a MOS transistor.

Claim 13

The large angle ion implanting method as claimed in claim 1, wherein said ion implanting method is applied to the formation of a contact region.