Abstract: Self-aligned trench MOSFETs and methods for manufacturing the same are disclosed. By having a self-aligned structure, the number of MOSFETS per unit area—the cell density—is increased, making the MOSFETs cheaper to produce. The self-aligned structure for the MOSFET is provided by making the sidewall of the overlying isolation dielectric layer substantially aligned with the sidewall of the gate conductor. Such an alignment can be made through any number of methods such as using a dual dielectric process, using a selective dielectric oxidation process, using a selective dielectric deposition process, or a spin-on-glass dielectric process.

Abstract: A semiconductor device is formed as follows. A plurality of trenches is formed in a silicon layer. An insulating layer filling an upper portion of each trench is formed. Exposed silicon is removed from adjacent the trenches to expose an edge of the insulating layer in each trench, such that the exposed edge of the insulating layer in each trench defines a portion of each contact opening formed between every two adjacent trenches.

Abstract: Various embodiments for improved power devices as well as their methods of manufacture, packaging and circuitry incorporating the same for use in a wide variety of power electronic applications are disclosed. One aspect of the invention combines a number of charge balancing techniques and other techniques for reducing parasitic capacitance to arrive at different embodiments for power devices with improved voltage performance, higher switching speed, and lower on-resistance. Another aspect of the invention provides improved termination structures for low, medium and high voltage devices. Improved methods of fabrication for power devices are provided according to other aspects of the invention. Improvements to specific processing steps, such as formation of trenches, formation of dielectric layers inside trenches, formation of mesa structures and processes for reducing substrate thickness, among others, are presented.

Abstract: In accordance with an embodiment of the present invention, a semiconductor device is formed as follows. An exposed surface area of a silicon layer where silicon can be removed is defined. A portion of the silicon layer is removed to form a middle section of a trench extending into the silicon layer from the exposed surface area of the silicon layer. Additional exposed surface areas of the silicon layer where silicon can be removed are defined. Additional portions of the silicon layer are removed to form outer sections of the trench such that the outer sections of the trench extend into the silicon layer from the additional exposed surface areas of the silicon layer. The middle section of the trench extends deeper into the silicon layer than the outer sections of the trench.

Abstract: A trenched field effect transistor is provided that includes (a) a semiconductor substrate, (b) a trench extending a predetermined depth into the semiconductor substrate, (c) a pair of doped source junctions, positioned on opposite sides of the trench, (d) a doped heavy body positioned adjacent each source junction on the opposite side of the source junction from the trench, the deepest portion of the heavy body extending less deeply into said semiconductor substrate than the predetermined depth of the trench, and (e) a doped well surrounding the heavy body beneath the heavy body.

Abstract: A power semiconductor device 10 has increased breakdown voltage due to an oxide termination structure. A peripheral trench 58 is filled with a dielectric material, such as silicon dioxide. The trench extends below the P well 22 that includes the source 32. The electric field at the border to P well 22 and trench 60 turns upward toward the surface and passes through dielectric 60. A field plate 64 coves portions of the P well 22 and the dielectric 60.

Abstract: In accordance with an embodiment of the present invention, a semiconductor device is formed as follows. An exposed surface area of a silicon layer where silicon can be removed is defined. A portion of the silicon layer is removed to form a middle section of a trench extending into the silicon layer from the exposed surface area of the silicon layer. Additional exposed surface areas of the silicon layer where silicon can be removed are defined. Additional portions of the silicon layer are removed to form outer sections of the trench such that the outer sections of the trench extend into the silicon layer from the additional exposed surface areas of the silicon layer. The middle section of the trench extends deeper into the silicon layer than the outer sections of the trench.

Abstract: A power semiconductor device 10 has increased breakdown voltage due to an oxide termination structure. A peripheral trench 58 is filled with a dielectric material, such as silicon dioxide. The trench extends below the P well 22 that includes the source 32. The electric field at the border to P well 22 and trench 60 turns upward toward the surface and passes through dielectric 60. A field plate 64 coves portions of the P well 22 and the dielectric 60.

Abstract: A method of making a trench MOSFET structure having upper trench corner protection, the method not requiring trench corner rounding or sacrificial oxide/strip steps. The trench MOSFET structure fabricated according to the method of the present invention exhibits higher oxide breakdown voltage and lower gate-to-source capacitance.

Abstract: Self-aligned trench MOSFETs and methods for manufacturing the same are disclosed. By having a self-aligned structure, the number of MOSFETS per unit area—the cell density—is increased, making the MOSFETs cheaper to produce. The self-aligned structure for the MOSFET is provided by making the sidewall of the overlying isolation dielectric layer substantially aligned with the sidewall of the gate conductor. Such an alignment can be made through any number of methods such as using a dual dielectric process, using a selective dielectric oxidation process, using a selective dielectric deposition process, or a spin-on-glass dielectric process.

Abstract: A process for manufacturing trench field effect transistors improves transistor ruggedness without compromising transistor cell pitch. Instead of a high dose implant and heat cycle, the process of the invention forms the transistor heavy body by etching a trench into the body region and filling the heavy body trench with high conductivity material such as metal that makes contact to both the body and the source region.