Development of a robust 50V 0.35 μm based Smart Power Technology using trench isolation

Next generation of Deep Trench Isolation for Smart Power technologies with 120V high-voltage devices

“…As a consequence, an incessant DTI development has been carried out during the last decade giving for a widespread of possibilities. The most of the reported DTI cross-sections [3][4][5][6][7][8][9][10][11] match with one of the (a)-(d) structures in Fig. 1.…”

“…(a) A deep trench filled with TEOS [3,10,11] or with TEOS and Polysilicon [4][5][6][7][8][9]. The latter is beneficial to avoid mechanical stress.…”

“…In the former case, the Polysilicon is highly doped and contacted to the bulk substrate by removing the oxide at the trench bottom. (c) A high resistive substrate [3,10] or a combination of high (top) with low (bottom) resistive regions in the substrate [4][5][6][7][8][9]11]. In order to provide different resistivity regions like in structures (c) and (d) in Fig.…”

“…In order to provide different resistivity regions like in structures (c) and (d) in Fig. 1, there exist two techniques: a high-dose implant through the trench [7,9,11] or a multiepitaxial substrate [4][5][6]8].…”

“…(a)-(d) Schematic cross-section of the previous DTI structures[3][4][5][6][7][8][9][10][11]. The new DTI structure with very deep trenches ($40 lm) is shown at the right side.…”