Semiconductor device having deep trench charge compensation regions and method
View Patent ↗In one embodiment, a semiconductor device is formed in a body of semiconductor material. The semiconductor device includes a charge compensating trench formed in proximity to active portions of the device. The charge compensating trench includes a trench filled with various layers of semiconductor material including opposite conductivity type layers.
1. A method of forming a semiconductor device comprising the steps of:
providing a body of semiconductor material having first and second opposing major surfaces;
forming a trench in the body of semiconductor material;
forming a first semiconductor layer of a first conductivity type adjoining surfaces of the trench;
forming a second semiconductor layer of a second conductivity type adjacent to the first semiconductor layer to form a charge compensating trench region;
forming a first doped region in the body of semiconductor material adjacent the charge compensating trench region, wherein the first doped region comprises the second conductivity type;
forming a second doped region in the first doped region and comprising the first conductivity type;
forming a control electrode adjacent the first and second doped regions;
forming a first intrinsic semiconductor layer between the first and second semiconductor layers; and
forming a conductive layer coupled to the charge compensating trench region.
2. The method of claim 1 wherein the step of forming the control electrode comprises forming a spacer gate structure.
3. The method of claim 1 further comprising the step of forming a passivation layer overlying the second semiconductor layer.
4. The method of claim 3 , wherein the step of forming the passivation layer comprises forming an oxide layer.
5. The method of claim 3 , wherein the step of forming the passivation layer comprises forming a dry oxide layer.
6. The method of claim 3 , wherein the step of forming the passivation layer comprises forming a nitride layer.
7. The method of claim 3 , wherein the step for forming the passivation layer comprises forming an oxide layer and a nitride layer.
8. The method of claim 3 further comprising the step of forming a void in the charge compensating trench region.
9. A method for forming a semiconductor device comprising the steps of:
providing a body of semiconductor material; and forming a trench in the body of semiconductor material forming a first layer comprising a single crystal semiconductor material overlying surfaces of the trench, wherein the first layer comprises a first conductivity type;
forming a first intrinsic layer overlying the first layer; forming a second layer comprising a single crystal semiconductor material overlying the first intrinsic layer, wherein the second layer comprises a second conductivity type, and wherein the first intrinsic layer is configured to reduce intermixing of dopants between the first and second layers;
forming a passivation layer overlying the second layer to form a charge compensation region; and
forming a conductive layer coupled to the charge compensating trench region.
10. The method of claim 9 , wherein the step of forming the passivation layer includes forming the passivation layer while leaving a void within the trench.
11. The method of claim 9 , wherein the step of forming the passivation layer includes forming a dry oxide layer.