Deep trench isolation of embedded DRAM for improved latch-up immunity
View Patent ↗A protective structure for blocking the propagation of defects generated in a semiconductor device is disclosed. In an exemplary embodiment, the structure includes a deep trench isolation formed between a memory storage region of the semiconductor device and a logic circuit region of the semiconductor device, the deep trench isolation being filled with an insulative material. The deep trench isolation thereby prevents the propagation of crystal defects generated in the logic circuit region from propagating into the memory storage region.
1. A method for blocking the propagation of defects generated in a semiconductor device, the method comprising:
forming a plurality of deep trench isolations between a memory storage region of the semiconductor device and a logic circuit region of the semiconductor device, and wherein said plurality of deep trench isolations surround said memory storage region; said plurality of deep trench isolations being filled with an insulative material;
configuring said deep trench isolations to form an inner perimeter and an outer perimeter, wherein individual deep trench isolations included in said outer perimeter are disposed adjacent to gaps in between individual deep trench isolations included in said inner perimeter; and
wherein said plurality of deep trench isolations prevent the propagation of crystal defects generated in said logic circuit region from propagating into said memory storage region.
2. The method of claim 1 , wherein said deep trench isolation is formed beneath a shallow trench isolation, said shallow trench isolation for electrically isolating devices contained in said memory storage region from devices contained in said logic circuit region.
3. The method of claim 1 , wherein said memory storage region comprises a DRAM array region.
4. The method of claim 3 , wherein said DRAM array region includes a plurality of deep trench storage capacitors.
5. The method of claim 4 , wherein said logic circuit region further includes:
a plurality of CMOS devices; and
a high dose impurity layer implanted within a substrate of said logic circuit region, said high dose impurity layer used to inhibit parasitic bipolar transistor action between said plurality of CMOS devices.