Groove power device structure and manufacturing method thereof

Abstract

The invention discloses a groove power device structure and a manufacturing method thereof. The groove power device structure comprises an active area and a terminal, wherein a groove is formed in a first photolithography mask layer from the outermost periphery of the active area to the edge of the device, an LOCOS area is arranged on a second photolithography mask layer, a contact hole is formed in the second photolithography mask layer, a source electrode and a grid electrode are arranged on a fourth photolithography mask layer, and groove isolation is combined with LOCOS. On the basis of advantages of various terminal structures, the structure is simple in process, low in cost, small in occupied area and wide in voltage application range and the like.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices and manufacturing methods thereof, in particular to a trench power device structure and a manufacturing method thereof. Background technique [0002] At present, Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Insulated Gate Bipolar Transistor (IGBT), Trench Metal Barrier Schottky Diode (TMBS) and Super Barrier Diode (SBD) are some of the most important power device. They are used in various fields of industrial electronics, home appliances and consumer electronics. They are inseparable from switching power supply circuits, rectifier circuits and drive circuits. Power devices require a large forward current and a large reverse voltage. Since the invention of power devices, improving their reverse withstand voltage capability has become an important issue. [0003] The withstand voltage capability of a power device consists of two parts: one is the withstand voltage of...

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Problems solved by technology

For example, the advantage of the pressure divider ring structure is that the process is relatively simple, but the disadvantage is that it occupies a large area and is greatly affected by the environment, so it needs to be covered with a protective layer; figure 2 The shown trench isolation structure uses the principle that the electric field is terminated on the sidewall of the trench to achieve the purpose of increasing the withstand voltage. This method is feasible for devices below 100V, because the voltage is low, and the depletion layer will not bypass the trench. However, as the voltage increases, the depletion layer also expands downward, and there is a risk of bypassing the trench. In order to solve this risk, the only way to deepen the trench is to bring the bottom of the trench It is easy to break down prematurely, so the problem that the breakdown at the bottom of the trench and the breakdown of the P-N junction cannot be satisfied at the same time, so trench isolation can only be applied to products below 100V

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