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
国产午夜男人天堂手机| 99人妻一区二区三区在线| 99热这里只有精品中文| 人妻少妇久久中文字幕久久| 欧美日韩国产亚洲免费| 韩国专区福利一区二区| 黑人精品少妇一区二区三区| 欧美日韩台湾一区二区| 国产精品国产三级国av中文| 国产亚洲精品视频在线网| 99久久久国产精品蜜臀 | 亚洲综合久久五月天| 在线成人免费日韩视频| 国产精品久久久久久爽| 99蜜桃臀成人美女视频| 日韩新片一区二区三区| 粗长挺进新婚人妻诗岚| 国产在线第一页第二页| 亚洲一区二区三区日韩欧美| 精品成人在线一区二区| 人人妻人人澡人人爽人人dvd| 免费在线一区二区av| 黄片大全视频在线免费观看| 亚洲国产精品自拍视频| 色哟哟亚洲精品一区二区| 四虎在线免费视频播放| 中文字幕在线五月婷婷| 亚洲欧美精品专区久久| 久久精品亚洲熟女av蜜謦| 久久伊人亚洲精品中文字幕| 色爱区偷拍人妻中文字幕| 在线观看免费国产k片| 亚洲中文无码亚洲人vr在线| 少妇人妻精品一区三区二区| 精品欧美激情精品一区| 亚洲一区二区另类视频| 久久伊人亚洲中文字幕| 久久综合色爱综合欧美| 亚洲性图中文字幕在线| 日操夜操天天操夜夜操| 无套内谢少妇高朝毛片|