Semiconductor devices and manufacturing methods thereof
View Patent ↗Semiconductor device fabrication methods include forming an oxide layer on a semiconductor substrate, forming an arrangement trench on the semiconductor substrate by patterning the oxide layer and the semiconductor substrate, forming a nitride layer on the arrangement trench and the oxide layer, forming a field trench on the semiconductor substrate by patterning the nitride layer, oxide layer, and the semiconductor substrate, and forming a pad oxide layer on inner walls of the field trench. The methods may also include removing the pad oxide layer on a bottom wall of the field trench, injecting ions into the bottom wall of the field trench so as to form an ion injected region, forming a buried layer by diffusing the ion injected region, and forming an epitaxial layer on the buried layer.
1. A method for fabricating a semiconductor device, comprising:
forming an oxide layer on a semiconductor substrate;
forming an arrangement trench on the semiconductor substrate by patterning the oxide layer and the semiconductor substrate;
forming a nitride layer on the arrangement trench and the oxide layer;
forming a field trench on the semiconductor substrate by patterning the nitride layer, oxide layer, and the semiconductor substrate;
forming a pad oxide layer on inner walls of the field trench;
removing the pad oxide layer on a bottom wall of the field trench;
injecting ions into the bottom wall of the field trench so as to form an ion injected region;
forming a buried layer by diffusing the ion injected region; and
forming an epitaxial layer on the buried layer.
2. A method as defined by claim 1 , wherein forming the arrangement trench includes:
forming an arrangement photoresist pattern on the oxide layer; and
etching the oxide layer and the semiconductor substrate using the arrangement photoresist pattern as an etch protection layer.
3. A method as defined by claim 1 , wherein forming the field trench includes:
forming a field photoresist pattern on the nitride layer; and
etching the nitride layer, the oxide layer, and the semiconductor substrate using the field photoresist pattern as an etch protection layer.
4. A method as defined by claim 1 , wherein the nitride layer and the oxide layer are removed after an epitaxial layer is formed on the buried layer.
5. A method as defined by claim 1 , wherein the ion injected into the bottom wall of the field trench comprises stibium (Sb).
6. A method as defined by claim 1 , wherein the arrangement trench is formed at a depth in the range of about 0.1 to 0.3 μm.
7. A method as defined by claim 1 , wherein the field trench is formed at a depth in the range of about 3 to 10 μm.
8. A method as defined by claim 1 , wherein the pad oxide layer is formed at a thickness in the range of about 450 to 550 Å.
9. A method as defined by claim 1 , wherein the semiconductor substrate comprises P+ type and the buried layer comprises N+ type.
10. A method as defined by claim 1 , wherein the buried layer is formed at a thickness in the range of about 1950 to 2050 Å.
11. A method as defined by claim 1 further comprising:
forming a protection nitride layer on surfaces of the oxide layer and the semiconductor substrate after the oxide layer is formed on the semiconductor substrate; and
removing the protection layer formed on the oxide layer.
12. A method for fabricating a semiconductor, comprising:
forming an oxide layer on the semiconductor substrate;
forming an arrangement trench on the semiconductor substrate by patterning the oxide layer and the semiconductor substrate;
forming a nitride layer on the arrangement trench and the oxide layer;
forming a field trench on the semiconductor substrate by patterning the nitride layer, the oxide layer, and the semiconductor substrate;
injecting ions on inner walls of the field trench so as to form an ion injected region;
forming a buried layer by diffusing the ion injected region; and
forming an epitaxial layer on the buried layer.