Method of fabricating a transistor channel structure with uniaxial strain
Method for creation of stressed channel structure transistors wherein at least one amorphizing ion implantation of the surface layer of a substrate of the semiconductor-on-insulator type is carried out through openings in a mask, so as to render zones of the surface layers amorphous and to induce relaxation of a zone intended to form a channel and located between the zones that have been rendered amorphous, the relaxation being carried out in a direction orthogonal to that in which it is intended that the channel current flows.
1. A method for creating stressed channel structure transistors comprising:
forming a mask on a surface layer of a semiconductor-on-insulator type substrate comprising a support layer, an insulating layer separating the support layer from the surface layer, the surface layer being based on a semiconductor material stressed with a biaxial stress, the mask being formed of plural blocks of elongated form arranged respectively on first zones of the surface layer, the first zones having a length measured parallel to a first direction and a width measured parallel to a second direction, said second direction being orthogonal to said first direction, the mask being configured such that several openings of elongated form and which extend parallel to the first direction are arranged on either side of the masking blocks and respectively reveal second zones of the surface layer arranged on either side of the first zones,
implanting of the surface layer through the openings in the mask, rendering the second zones amorphous and inducing relaxation of the first zone in the second direction by the implanting, and
after amorphisation of the second zones of the surface layer,
removing the mask, then
forming at least one transistor gate extending parallel to the second direction,
growing, on the surface layer, a source block and a drain block on either side of the transistor gate,
the method further comprising: transforming the second zones of the surface layer revealed by the openings of the mask into insulating zones,
wherein said gate is arranged on plural first zones and plural second zones, wherein said source block is arranged on said plural first zones and said plural second zones, said plural first zones being configured to form a transistor channel structure.
2. The method according to claim 1 wherein the transformation of the second zones into insulating zones is achieved using at least one implantation step.
3. The method according to claim 2 , wherein the amorphisation of the second zones and the transformation of the second zones into insulating zones are carried out concomitantly by implantation.
4. The method according to claim 2 wherein the transformation of the second zones into insulating zones comprises at least one thermal oxidation step.
5. The method according to claim 1 , wherein at least one insulating zone formed by transformation of the second zones, forms a separation with another transistor.
6. The method according to claim 1 wherein, after transformation of the second zones that have been rendered amorphous into insulating zones, a thickness of these insulating zones is removed.
7. The method according to claim 1 , wherein the mask has an intrinsic stress.
8. A method for creating stressed channel structure transistors, said method comprising:
forming a mask on a surface layer of a semiconductor-on-insulator type substrate comprising a support layer, an insulating layer separating the support layer from the surface layer, the surface layer being based on a semiconductor material stressed with a biaxial stress, the mask being formed from at least one block of elongated form arranged on a first zone of the surface layer, the first zone having a length measured parallel to a first direction and a width measured parallel to a second direction, the first zone being capable of forming a transistor channel structure wherein a current is meant to pass in the first direction, the mask being configured such that one or several openings of elongated form and which extend parallel to the first direction are arranged on either side of the masking block and respectively reveal the second zones of the surface layer arranged on either side of the first zone,
executing at least one ion implantation of the surface layer through the openings in the mask, so as to render the second zones amorphous and to induce relaxation of the first zone in the second direction,
transforming the second zones of the surface layer revealed by the openings of the mask into insulating zones,
wherein the mask is a first mask, the method further comprising, after forming the first mask and prior to the amorphisation of the second zones, forming a second mask resting on the first mask and arranged opposite given regions of the surface layer, the second mask comprising an opening revealing the first mask, then after amorphisation of the second zones:
removing a portion of the first mask through the opening of the second mask,
forming a gate in the opening of the second mask,
removing the second mask and of remaining portions of the first mask, then,
forming source and drain blocks on either side of the gate.
9. A method for creating stressed channel structure transistors, said method comprising:
forming a mask on a surface layer of a semiconductor-on-insulator type substrate comprising a support layer, an insulating layer separating the support layer from the surface layer, the surface layer being based on a semiconductor material stressed with a biaxial stress, the mask being formed from at least one block of elongated form arranged on a first zone of the surface layer, the first zone having a length measured parallel to a first direction and a width measured parallel to a second direction, the first zone being capable of forming a transistor channel structure wherein a current is meant to pass in the first direction, the mask being configured such that one or several openings of elongated form and which extend parallel to the first direction are arranged on either side of the masking block and respectively reveal the second zones of the surface layer arranged on either side of the first zone,
executing at least one ion implantation of the surface layer through the openings in the mask, so as to render the second zones amorphous and to induce relaxation of the first zone in the second direction,
transforming the second zones of the surface layer revealed by the openings of the mask into insulating zones,
wherein, prior to the formation of the mask, the following steps are carried out:
forming a sacrificial gate on the surface layer, then,
forming source and drain blocks on either side of the sacrificial gate,
removing the sacrificial gate so as to leave room for an opening between the source and drain blocks,
then, after forming the mask in the opening and amorphisation of the second zones of the surface layer, a gate is formed in the opening between the source and drain blocks.
10. The method according to claim 1 , wherein
the removing the mask includes revealing the surface layer including the first zones and the second zones,
the forming the at least one transistor gate includes forming the at least one transistor gate on the surface layer, the at least one transistor gate having an elongated dimension in the second direction, and
the growing the source block and the drain block includes growing the source block and the drain block on either side of the transistor gate in the first direction.