高潮内射大片一区二区-中文字幕一区二区三区女同性恋-亚洲熟乱熟女妇综合网二区-日韩成人免费av电影

技術(shù)文章/ article

您的位置:首頁  -  技術(shù)文章  -  微加工:剝離

微加工:剝離

更新時間:2015-08-06      瀏覽次數(shù):3103

Lift-off process in microstructuring technology is a method of creating structures (patterning) of a target material on the surface of a substrate (ex. wafer) using a sacrificial material (ex. Photoresist). It is an additive technique as opposed to more traditional subtracting technique like etching. The scale of the structures can vary from the nanoscale up to the centimeter scale or further, but are typically of micrometric dimensions.

Process

An inverse pattern is first created in the sacrificial stencil layer (ex. photoresist), deposited on the surface of the substrate. This is done by etching openings through the layer so that the target material can reach the surface of the substrate in those regions, where the final pattern is to be created. The target material is deposited over the whole area of the wafer, reaching the surface of the substrate in the etched regions and staying on the top of the sacrificial layer in the regions, where it was not previously etched. When the sacrificial layer is washed away (photoresist in a solvent), the material on the top is lifted-off and washed together with the sacrificial layer below. After the lift-off, the target material remains only in the regions where it had a direct contact with the substrate.

·       Substrate is prepared

·       Sacrificial layer is deposited and an inverse pattern is created (ex. photoresist is exposed and developed. Depending on the resist various methods can be used, such as Extreme ultraviolet lithography - EUVL or Electron beam lithography - EBL. The photoresist is removed in the areas, where the target material is to be located, creating an inverse pattern.)

·       Target material (usually a thin metal layer) is deposited (on the whole surface of the wafer). This layer covers the remaining resist as well as parts of the wafer that were cleaned of the resist in the previous developing step.

·       The rest of the sacrificial material (ex. photoresist) is washed out together with parts of the target material covering it, only the material that was in the "holes" having direct contact with the underlying layer (substrate/wafer) stays

Advantages

Lift-off is applied in cases where a direct etching of structural material would have undesirable effects on the layer below.

Disadvantages

There are 3 major problems with lift-off:

Retention

This is the worst problem for liftoff processes. If this problem occurs, unwanted parts of the metal layer will remain on the wafer. This can be caused by different situations. The resist below the parts that should have been lifted off could not have dissolved properly. Also, it is possible that the metal has adhered so well to the parts that should remain that it prevents lift-off.

Ears

When the metal is deposited, and it covers the sidewalls of the resist, "ears" can be formed. These are made of the metal along the sidewall which will be standing upwards from the surface. Also, it is possible that these ears will fall over on the surface, causing an unwanted shape on the substrate.

If the ears remain on the surface, the risk remains that these ears will go through different layers put on top of the wafer and they might cause unwanted connections.

Redeposition

During the liftoff process it is possible that particles of metal will become reattached to the surface, at a random location. It is very difficult to remove these particles after the wafer has dried.

Use

Lift-off process is used mostly to create metallic interconnections.
There are several types of lift-off processes, and what can be achieved depends highly on the actual process being used. Very fine structures have been used using EBL, for instance. The lift-off process can also involve multiple layers of different types of resist. This can for instance be used to create shapes that will prevent side walls of the resist being covered in the metal deposition stage.

*Please contact us if there is problem using this passage* 

返回列表

版權(quán)所有©2025 那諾中國有限公司 All Rights Reserved   備案號:   sitemap.xml   技術(shù)支持:化工儀器網(wǎng)   管理登陸
一区二区三区一级黄色| 最近最新免费成人在线视频| 日韩免费视频一区二区三区免费| 亚洲中文字幕乱码第一页| 国产精品偷伦一区二区| 麻豆精品国产一区二区91| 啄木乌法国一区二区三区| 中文字幕一区二区精品人妻| 亚洲国产成人精品av在线| 国产亚洲一区二区三区午夜| 男人午夜激情免费网站| 国产乱子一区二区三区| 亚洲人色中文字幕天堂| 亚洲精品成人午夜久久| 日本韩国精品视频在线| 亚洲精品尤物福利在线一区| 国产亚洲欧美精品久久久久久| 成人欧美一区二区三区av| 青青草原这里只有精品| 一区二区三区在线观看淫| 国产成人精品福利一区二区| 日日夜夜天天操天天干| 91日本视频在线播放| 亚洲精品一区二区三区香蕉| 国产精品中文字幕日韩在线| 国产欧美激情一区二区 | 日韩欧美国产亚洲在线| 亚洲精品尤物福利在线一区| 97久久精品国产成人影院| 少妇视频资源一区二区三区| 亚洲日本乱码一区二区三| 国产精品熟女亚洲av| 午夜理论片在线观看有码| 在线观看成人激情视频| 九九九视频在线观看免费| 高清一区二区三区不卡视频| 亚洲免费黄色大片网站| 欧美日韩伦理片在线观看| 人人妻人人澡人人爽的视频| 夜夜高潮夜夜爽免费观看| 丰满肥臀熟女高清区二区|