Edge encapsulation for high voltage devices
A semiconductor device architecture includes a silicon substrate having sidewalls that are passivated by encapsulating the sidewalls in dielectric materials having high electric field strength. Encapsulating all the sidewalls using high field strength dielectric materials eliminates electrical paths in air or vacuum and confines the electric fields in these high field strength materials, increasing the breakdown voltage relative to unencapsulated devices and allowing the device to withstand greater standoff voltages. In some cases, encapsulating the sidewalls in this manner can allow the device to withstand voltages of 500V or greater.
1. A method for fabricating a semiconductor device, comprising:
depositing, within a silicon substrate of a wafer on which semiconductor devices are formed, vertical layers of one or more materials having a high field strength at boundaries of the semiconductor devices; and
separating the semiconductor devices to yield singulated semiconductor devices having sidewalls that are encapsulated by the one or more materials, wherein encapsulation sidewalls by the one or more materials enables the singulated semiconductor devices to withstanding standoff voltages between components on the singulated semiconductor devices of 500 volts or more.
2. The method of claim 1 , wherein the depositing comprises depositing vertical layers of at least one of thermal oxide, silicon nitride, borosilicate glass, aluminum oxide (Al2O3), aluminum nitride (AlN), hafnium oxide (HfO2), hafnium nitride (HfN), lanthanum oxide (La2O3), silicon dioxide (SiO2), titanium dioxide (TiO2), zinc oxide (ZnO), zirconium oxide (ZrO2), scandium oxide (Sc2O3), gallium trioxide (Ga2O3), or high temperature polymer.
3. The method of claim 1 , wherein the singulated semiconductor devices are capable of withstanding standoff voltages between components on the singulated semiconductor devices of 1,000 volts or more.
4. The method of claim 1 , wherein the depositing comprises:
depositing a layer of silicon nitride on the sidewalls; and
depositing a layer of borosilicate glass on the layer of silicon nitride.
5. The method of claim 1 , wherein the depositing comprises:
depositing a layer of thermal oxide on the sidewalls;
depositing a layer of silicon nitride on the layer of thermal oxide; and
depositing a layer of borosilicate glass on the layer of silicon nitride.
6. The method of claim 1 , wherein the depositing comprises:
depositing a layer of thermal oxide on the sidewalls;
depositing a layer of silicon nitride on the layer of thermal oxide; and
depositing a layer of high temperature polymer on the layer of silicon nitride.
7. The method of claim 1 , wherein the semiconductor device is at least one of a diode, a transistor, a thyristor, a capacitor, a resistor, an inductor, a filter, or a high-electron-mobility transistor (HEMT) device.
8. The method of claim 1 , wherein the depositing comprises:
depositing a layer of silicon nitride on the sidewalls.
9. The method of claim 1 , wherein the depositing comprises:
depositing a layer of thermal oxide on the sidewalls.
10. The method of claim 1 , wherein the separating comprises:
sawing the semiconductor devices to yield the singulated semiconductor devices.
11. The method of claim 1 , wherein the separating comprises:
laser cutting the semiconductor devices to yield the singulated semiconductor devices.
12. The method of claim 1 , wherein the separating comprises:
etching the semiconductor devices to yield the singulated semiconductor devices.
13. The method of claim 1 , wherein the separating comprises:
scribing the semiconductor devices to yield the singulated semiconductor devices.
14. The method of claim 1 , wherein the one or more materials comprise a dielectric material.
15. The method of claim 1 , wherein the semiconductor devices comprise active semiconductor devices.
16. The method of claim 1 , wherein the semiconductor devices comprise passive semiconductor devices.
17. The method of claim 1 , wherein all sidewalls of each singulated semiconductor device are encapsulated by the one or more materials.
18. The method of claim 1 , wherein the one or more materials comprise an inorganic insulator.
19. The method of claim 1 , wherein the one or more materials comprise a high field strength polymer.
20. The method of claim 1 , wherein the singulated semiconductor devices are capable of withstanding standoff voltages between components on the singulated semiconductor devices of 3,000 volts or more.