Junction field effect transistor

A junction field effect transistor, comprising:

• a first semiconductor layer of a first conductivity type;
• an element isolation insulator disposed on an upper layer portion of the first semiconductor layer to partition an active area;
• a second semiconductor layer of a second conductivity type, on the first semiconductor layer in the active area, the second semiconductor layer having an end in a first direction separated from the element isolation insulator;
• a source layer of the second conductivity type, on the second semiconductor layer, the source layer having an impurity concentration higher than an impurity concentration of the second semiconductor layer;
• a drain layer of the second conductivity type, on the second semiconductor layer, and separated from the source layer in a second direction intersecting the first direction, the drain layer having an impurity concentration higher than the impurity concentration of the second semiconductor layer;
• a gate layer of the first conductivity type, on the second semiconductor layer, between the source layer and the drain layer, and separated from the source layer and the drain layer;
• a salicide layer on an upper surface of each of the source layer, the drain layer, and the gate layer;
• a source contact on an upper surface of the salicide layer on the upper surface of the source layer;
• a gate contact on an upper surface of the salicide layer on the upper surface of the gate layer;
• and
• a drain contact on an upper surface of the salicide layer on the upper surface of the drain layer,
• wherein, when the junction field effect transistor is turned ON, a source-to-drain current flows from the source layer to the second semiconductor layer that is below the gate layer and then to the drain layer.

A junction field effect transistor, comprising:

• a first semiconductor layer of a first conductivity type;
• an element isolation insulator disposed on an upper layer portion of the first semiconductor layer to partition an active area that extends in a first direction;
• a second semiconductor layer of a second conductivity type, on the first semiconductor layer in the active area, the second semiconductor layer also extending in the first direction, both ends of the active area in the first direction extending further in the first direction than both ends of the second semiconductor layer in the first direction;
• a source layer of the second conductivity type, on the second semiconductor layer, the source layer having an impurity concentration higher than an impurity concentration of the second semiconductor layer;
• a drain layer of the second conductivity type, on the second semiconductor layer, and separated from the source layer in a second direction intersecting the first direction, the drain layer having an impurity concentration higher than the impurity concentration of the second semiconductor layer;
• and
• a gate layer of the first conductivity type, on the second semiconductor layer, between the source layer and the drain layer, and separated from the source layer and the drain layer.