Method for making micro reflector layer and silicon based LCD

Abstract

A method for fabricating a micromirror layer comprises the following steps: providing a semiconductor substrate which sequentially comprises a metal interlayer dielectric layer with a bonding pad groove, defective micromirror layers and a mirror protection layer, wherein, the defective micromirror layers are isolated by a first dielectric layer; filling the bonding pad groove with an oxide layer; smoothening the first dieletric layer and the oxide layer to expose an insulating layer after the removal of the mirror protection layer and the defective micromirror layers; forming metal layers on the metal interlayer dielectric layer and the oxide layer of the bonding pad groove; forming a photoresist layer on the metal layers and defining a graph of the micromirror layer; etching the metal layers with the photoresist layer as a mask to expose the metal interlayer dielectric layer, thus forming the micromirror layer; and removing the photoresist layer and forming the a dieletric layer between the micromirror layers. The invention also provides a method for fabricating a silicon-based LCD. The method ensures the same size of the final micromirror layers and improves the quality of the micromirror layers.

Description

technical field [0001] The invention relates to a method for manufacturing a semiconductor device, in particular to a method for manufacturing a microreflector layer and a silicon-based liquid crystal display. Background technique [0002] Liquid crystal on silicon (LCOS) is a new type of reflective liquid crystal display device. Unlike ordinary liquid crystals, LCOS combines CMOS technology to directly realize the driving circuit on the silicon wafer, and uses CMOS technology to make the active pixel matrix on the silicon substrate. On the bottom, it has the characteristics of small size and high resolution. [0003] An ideal LCOS should be flat, smooth and have high reflectivity, so as to ensure the consistency of the liquid crystal layer thickness and not distort the light, which requires that the reflector surface must be quite flat to accurately control the reflected light path , which is a very critical factor for high-end applications such as projection TVs. [0004...

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Problems solved by technology

[0004] In the existing process of making the micro-mirror layer, the micro-mirror layer often has defects 10 (such as figure 1 shown in the middle oval)

[0014] In the prior art, a photoresist layer is formed on the metal layer by spin coating, and the thickness of the photoresist is controlled by the speed of spin coating. Since there is a pad groove with a certain depth at the pad connection layer, the pad groove The photoresist layer inside is easily thrown out, which leads to uneven thickness of the photoresist layer on the metal layer. In the subsequent exposure and development process, the defined micro-mirror size appears in the area of ​​different thickness of the photoresist layer. Systematic differences lead to differences in the size of the final micro-mirror layer, and the meaning of re-making the micro-mirror layer is lost

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