Ultra-high voltage SIGE HBT device and manufacturing method of the same
An ultra-high voltage silicon-germanium (SiGe) heterojunction bipolar transistor (HBT), which includes: a P-type substrate; an N-type matching layer, a P-type matching layer and an N− collector region stacked on the P-type substrate from bottom up; two field oxide regions separately formed in the N− collector region; N+ pseudo buried layers, each under a corresponding one of the field oxide regions and in contact with each of the N-type matching layer, the P-type matching layer and the N− collector region; an N+ collector region between the two field oxide regions and through the N− collector region and the P-type matching layer and extending into the N-type matching layer; and deep hole electrodes, each in a corresponding one of the field oxide regions and in contact with a corresponding one of the N+ pseudo buried layers. A method of fabricating an ultra-high voltage SiGe HBT is also disclosed.
1. An ultra-high voltage silicon-germanium (SiGe) heterojunction bipolar transistor (HBT), comprising:
a P-type substrate with a low dopant concentration;
an N-type matching layer, a P-type matching layer and an N− collector region formed on the P-type substrate from the bottom up;
two separate field oxide regions in the N− collector region;
N+ pseudo buried layers, each under a corresponding one of the field oxide regions and in contact with each of the N-type matching layer, the P-type matching layer and the N− collector region;
an N+ collector region between the two field oxide regions, the N+ collector region being formed through the N− collector region and the P-type matching layer and extending into the N-type matching layer; and
deep hole electrodes, each in a corresponding one of the field oxide regions and in contact with a corresponding one of the N+ pseudo buried layers.
2. The ultra-high voltage SiGe HBT according to claim 1 , wherein dopant concentrations of the N-type and P-type matching layers are determined by a dopant concentration of the N+ collector region.
3. The ultra-high voltage SiGe HBT according to claim 1 , wherein the N− collector region has a same dopant concentration with the N-type matching layer, and wherein the N− collector region is doped with arsenic ions or phosphorus ions.
4. The ultra-high voltage SiGe HBT according to claim 1 , wherein the N+ pseudo buried layers are doped with arsenic ions or phosphorus ions with a high dose of 1e 14 cm −2 to 1e 16 cm −2 and a low energy of 2 KeV to 50 KeV.
5. The ultra-high voltage SiGe HBT according to claim 1 , wherein the N+ collector region is heavily doped with arsenic ions or phosphorus ions with a high dose.
6. The ultra-high voltage SiGe HBT according to claim 1 , wherein each of the deep hole electrodes includes a transition metal layer and a tungsten, and wherein the transition metal layer includes a titanium layer and a titanium nitride layer.
7. The ultra-high voltage SiGe HBT according to claim 1 , further comprising:
a SiGe base region above both the field oxide regions and the N+ collector region; and
an emitter above the SiGe base region.
8. A method of manufacturing ultra-high voltage silicon-germanium (SiGe) heterojunction bipolar transistor (HBT), comprising the steps of:
1) sequentially growing, by epitaxy, an N-type matching layer and a P-type matching layer over a P-type substrate having a low dopant concentration;
2) depositing an epitaxial layer having a moderate to low dopant concentration over the P-type matching layer, the epitaxial layer serving as an N− collector region;
3) forming two separate shallow trenches in the N− collector region and forming field oxide regions by filling silicon oxide in the shallow trenches;
4) forming N+ pseudo buried layers by implanting ions into the N-type and P-type matching layers;
5) forming an N+ collector region between the field oxide regions, the N+ collector region being formed through the N− collector region and the P-type matching layer and extending into the N-type matching layer;
6) forming a SiGe base region above both the field oxide regions and the N+ collector region;
7) forming an emitter above the SiGe base region; and
8) forming a deep hole electrode in each of the field oxide regions by etching each of the field oxide regions to form a deep hole therein which exposes an underlying corresponding one of the N+ pseudo buried layers and depositing a transition metal layer and filling tungsten in the deep hole.
9. The method according to claim 8 , wherein dopant concentrations of the N-type and P-type matching layers formed in the step 1) are determined by a dopant concentration of the N+ collector region.
10. The method according to claim 8 , wherein the N− collector region formed in the step 2) has a same dopant concentration with the N-type matching layer, and wherein the N-collector region is doped with arsenic ions or phosphorus ions.
11. The method according to claim 8 , wherein the N+ pseudo buried layers formed in the step 4) are doped with arsenic ions or phosphorus ions with a high dose of 1e 14 cm −2 to 1e 16 cm −2 and a low energy of 2 KeV to 50 KeV.
12. The method according to claim 8 , wherein the N+ collector region formed in the step 5) is heavily doped with arsenic ions or phosphorus ions with a high dose.
13. The method according to claim 8 , wherein in the step 8), the transition metal layer is deposited by PVD or CVD.