Lateral bipolar junction transistor with controlled junction
A method of forming a lateral bipolar junction transistor (LBJT) that includes providing a germanium containing layer on a crystalline oxide layer, and patterning the germanium containing layer stopping on the crystalline oxide layer to form a base region. The method may further include forming emitter and collector extension regions on opposing sides of the base region using ion implantation, and epitaxially forming an emitter region and collector region on the crystalline oxide layer into contact with the emitter and collector extension regions. The crystalline oxide layer provides a seed layer for the epitaxial formation of the emitter and collector regions.
1. A lateral bipolar junction transistor (LBJT) device comprising:
a crystalline oxide layer;
a base region comprised of a germanium containing material in direct bonded engagement to the crystalline oxide layer;
an extrinsic base region formed on the germanium containing material;
a spacer formed on sidewalls of the extrinsic base region;
an emitter region and collector region epitaxially formed on opposing sides of the base region, the emitter region and collector region being in an epitaxial relationship with the crystalline oxide layer; and
an emitter extension region and collector extension region formed between each of the emitter region and the collector region and the base region.
2. The lateral bipolar junction transistor (LBJT) of claim 1 , wherein the emitter and collector extension regions have a dopant conductivity equal to the emitter and the collector region, wherein a vertical dopant concentration in said emitter and collector extension regions is substantially uniform.
3. The lateral bipolar junction transistor (LBJT) of claim 2 , wherein a dopant concentration in said emitter and collector extension regions ranges from 1×10 19 cm −3 to 1×10 21 cm −3 .
4. The lateral bipolar junction transistor (LBJT) of claim 3 , wherein the emitter region and collector region are composed of facetted or non-facetted semiconductor material.
5. The lateral bipolar junction transistor (LBJT) of claim 4 , wherein the emitter and collector region are comprised of an epitaxial semiconductor selected from the group consisting of polysilicon, polysilicon germanium and a combination thereof.
6. The lateral bipolar junction transistor (LBJT) device of claim 1 , wherein the extrinsic base region comprised of a semiconductor selected from the group consisting of doped poly-silicon, doped poly-silicon germanium and a combination thereof, wherein a dopant concentration that provides a conductivity type of the extrinsic base region is greater than a dopant concentration that provides a conductivity type of the base region.
7. The lateral bipolar junction transistor (LBJT) device of claim 1 , wherein the crystalline oxide is selected from the group consisting of cerium oxide (CeO 2 ), lanthanum oxide (La 2 O 3 ), yttrium oxide (Y 2 O 3 ), gadolinium oxide (Gd 2 O 3 ), europium oxide (Eu 2 O 3 ), terbium oxide (Tb 2 O 3 ) or combinations thereof.
8. A method of forming a lateral bipolar junction transistor (LBJT) comprising:
providing a germanium containing layer directly bonded to a crystalline oxide layer;
patterning the germanium containing layer stopping on the crystalline oxide layer to form a base region;
forming an emitter extension region and collector extension regions on opposing sides of the base region using ion implantation; and
epitaxially forming an emitter region and collector region on the crystalline oxide layer into contact with the emitter and collector extension regions.
9. The method of claim 8 , wherein said providing the germanium containing layer on the crystalline oxide layer comprises:
forming a first material stack comprising said germanium containing layer, the first material stack further comprises a buried oxide region separating the germanium containing layer from a supporting substrate;
forming a second material stack comprising said crystalline oxide layer, wherein the second material stack further comprises a sacrificial oxide layer separating said germanium containing layer from a handling substrate;
bonding the first material stack to the second material stack through contact between the germanium containing layer and the crystalline oxide layer; and
removing the handling substrate and the sacrificial oxide layer.
10. The method of claim 9 further comprising:
forming an extrinsic base material layer of a doped semiconductor selected from the group consisting of doped polycrystalline silicon material, doped polycrystalline germanium and combinations thereof;
forming a hard mask on the extrinsic base material layer;
etching the extrinsic base material layer selective to the hard mask and the germanium containing layer to pattern an extrinsic base region;
forming a spacer on the sidewalls of said extrinsic base region; and
etching the germanium containing layer to pattern the base region with an etch that is selective to the hard mask and the spacer prior to said forming emitter and collector extension regions.
11. The method of claim 10 , wherein the etching of the germanium containing layer to pattern the base region is selective to the crystalline oxide layer.
12. The method of claim 11 , wherein said forming emitter and collector extension regions comprises performing an angled ion implantation to produce an emitter and collector junction on opposing sides of the base region.
13. The method of claim 12 , wherein said epitaxially forming the emitter region and the collector region on the crystalline oxide layer into contact with the emitter and collector extension regions uses the crystalline oxide layer as a seed layer.
14. The method of claim 13 , wherein the emitter region and collector region comprise polycrystalline or single crystalline semiconductor material, wherein the polycrystalline or single crystalline semiconductor material is grown on the nucleation dielectric layer.
15. The method of claim 8 , wherein the crystalline oxide layer is selected from the group consisting of cerium oxide (CeO 2 ), lanthanum oxide (La 2 O 3 ), yttrium oxide (Y 2 O 3 ), gadolinium oxide (Gd 2 O 3 ) europium oxide (Eu 2 O 3 ), terbium oxide (Tb 2 O 3 ), and combinations thereof.
16. The method of claim 1 , wherein the emitter region and the collector region comprise semiconductor material having a larger band gap than the base region.
17. A method of forming a lateral bipolar junction transistor (LBJT) comprising:
providing a germanium containing layer directly on a crystalline oxide layer;
forming an extrinsic base region on the germanium containing layer;
forming a spacer on sidewalls of the extrinsic base region;
etching the germanium containing layer using the extrinsic base region and said spacer as a mask with an etch that is selective to the crystalline oxide layer to form a base region;
forming an emitter extension region and collector extension region on opposing sides of the base region using angled ion implantation; and
epitaxially forming an emitter region and collector region on the crystalline oxide layer into contact with the emitter extension region and collector extension region.
18. The method of claim 17 , wherein said epitaxially forming the emitter region and the collector region on the crystalline oxide layer into contact with the emitter extension region and collector extension regions uses the crystalline oxide layer as a seed layer.
19. The method of claim 18 , wherein the emitter region and collector region comprise polycrystalline or single crystalline semiconductor material, wherein the polycrystalline or single crystalline semiconductor material is grown on the nucleation dielectric layer.
20. The method of claim 17 , wherein the crystalline oxide layer is selected from the group consisting of cerium oxide (CeO 2 ), lanthanum oxide (La 2 O 3 ), yttrium oxide (Y 2 O 3 ), gadolinium oxide (Gd 2 O 3 ), europium oxide (Eu 2 O 3 ), terbium oxide (Tb 2 O 3 ), and combinations thereof.