Method of forming shallow junctions
AssigneeFujitsu Limited
InventorsMasahiko Doki, Michiko Takei
Life of this patent
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Abstract
A method of forming a shallow junction comprises the step of: forming a film including a hydrogen compound with one element selected from the group of boron, phosphorus arsenic to a thickness of several atom layers to 1000 .ANG. on a silicon substrate and annealing the film, whereby an impurity region having a depth of 1000 .ANG. or less and an impurity concentration of 10.sup.18 to 10.sup.21 cm.sup.-3 is formed in the surface layer of the silicon layer.
Claims11
A method of forming a shallow junction comprising the steps of:
- forming a film of a hydrogen compound of an element selected from the group consisting of boron, phosphorus and arsenic and having a thickness of from several atom layers to 1000 .ANG. on a silicon layer, without impurities substantially penetrating said silicon layer by depositing said compound at a temperature of up to 150.degree. C. and an accelerating energy of up to 20V;
- and
- annealing the film under conditions sufficient to form an impurity region having a depth of 1000 .ANG. or less and having an impurity concentration of 10.sup.18 to 10.sup.21 in the surface layer of the silicon layer.
A method of producing an npn type bipolar transistor having a shallow junction, comprising the steps of:
- forming a film of a hydrogen compound of an element selected from a group consisting of boron, phosphorus and arsenic on a first conductivity type silicon layer acting as a collector, under such conditions, including a temperature of up to 150.degree. C. and an acceleration energy of up to 20V, as not to damage said silicon layer;
- annealing the film and the silicon layer to diffuse the one element included in the film into the n type silicon so that a base having a thickness of 1000 .ANG. or less is formed;
- and
- forming an emitter of a silicon layer containing said first conductivity type impurities on part of the base.
A method of producing a MOS transistor having a shallow source and drain, comprising the steps of:
- forming a gate insulating layer and a gate electrode on a first conductivity type silicon layer;
- forming a film of a hydrogen compound of an element selected from the group consisting of boron, phosphorus and arsenic on said first conductivity type silicon layer, under such conditions, including a temperature of up to 150.degree. C. and an acceleration energy of up to 20V, as not to damage said silicon layer;
- annealing the film and said first conductivity type silicon layer to diffuse the one element selected from the group consisting of boron, phosphorus and arsenic into said silicon layer, wherein a second conductivity type silicon layer having a thickness of 1000 .ANG. or less and an impurity concentration of 10.sup.8 to 10.sup.21 cm.sup.-3 is formed in said first conductivity type silicon layer;
- forming a drain formation mask at the side wall of the gate electrode;
- and
- introducing a second conductivity type impurity into the first conductivity type silicon layer using both the gate electrode and the side wall thereof as a mask.
Dependencies are inferred from the claim text.