Polysilicon etching cavity and method capable of lowering metal pollutant content in cavity

Abstract

The invention discloses a polysilicon etching cavity and a method capable of lowering metal pollutant content in the cavity. A plasma isolation apparatus is arranged on the exterior of an exposed top assembling structure of metal nails, wherein the metal nails are used for tightly locking a static adsorption plate, a lower electrode, a focus ring and a base; the metal nails are fully protected, so that the problem that the metal nails are subjected to etching plasma bombardment to generate metal active ions to cause metal pollution to the etching cavity in the cavity process period can be avoided completely; and an effect of lowering the metal pollutant content in the polysilicon etching cavity is achieved, thereby lowering inherent damage to the electrical performance of the product in the polysilicon etching process, and improving the product yield.

Description

technical field [0001] The invention relates to the field of microelectronics, in particular to a polysilicon etching chamber and method capable of reducing metal pollution content in the chamber. Background technique [0002] see figure 1 , figure 1 It is a schematic diagram of the internal structure of an existing polysilicon etching chamber. like figure 1 As shown, the polysilicon etching chamber 10 is provided with an electrostatic adsorption plate 14 for absorbing and fixing the silicon wafer 15 on the surface of the electrostatic adsorption plate 14 for processing. A lower electrode 12 is provided below the electrostatic adsorption disk 14 , a base 11 is provided below the lower electrode 12 , and a focus ring 13 is provided around the electrostatic adsorption disk 14 for protecting the lower electrode 12 below it. [0003] read on figure 1 . In the design of the electrostatic adsorption disc of the existing polysilicon etching machine, the nails 16 used to lock ...

AI Technical Summary

Problems solved by technology

When the metal nail 16 is bombarded, it will excite a large amount of metal active ions and distribute them inside the etching chamber 10, causing the problem of metal pollution to the etching chamber 10.

Moreover, these metal active ions will be injected into the silicon wafer 15 under the action of strong pressure and strong current during the process, thus greatly affecting the electrical properties of the product

Images