Developer Solution
Product Description
https://www.by-micro.com/developer.html
Semiconductor developer solutions are chemical mixtures used in the photolithography process to develop photoresist patterns on silicon wafers. These solutions selectively remove exposed or unexposed photoresists, depending on the type used.
The developer is a chemical solvent that dissolves the photoresist (PR) produced by exposure. The PR in the photolithography process is mainly divided into positive PR and negative PR, so the developer is divided into positive PR developer and negative PR developer. The positive PR developer is usually a strong alkaline solution diluted with water, which is used in the positive PR development process. The negative PR developer is usually an organic solvent, which is used in the negative PR development process.
Development Mechanism
In order to partially dissolve the PR and obtain the pattern in the PR coating, a suitable developer must be used. The part of the positive PR that is not irradiated by the exposure lamp will be retained after development, while the part of the negative PR that is not irradiated by the exposure lamp will be dissolved after development. Simply put, during the development process, the photosensitive area of the positive PR and the non-photosensitive area of the negative PR are dissolved in the developer. The development mechanism of the positive PR developer and the negative PR developer is an acid-base neutralization reaction, but it is slightly different.
Positive PR developers: Positive PR developers have a dissolving effect on positive PR. After exposure, positive PR is acidic and can be neutralized with alkaline positive PR developers. Adding appropriate buffers to positive PR developers can maintain the pH balance of the developer so that the developer concentration does not change too quickly. Therefore, adding buffers is beneficial to the development effect.
Negative PR developers: Negative PR developers have a dissolving effect on negative PR. The unexposed area of negative PR is weakly acidic and can be neutralized with alkaline negative PR developers. Negative PR has a large molecular weight and strong hydrophobicity, so surfactants are usually added to negative PR developers to improve its hydrophilicity and ensure the development effect.
