DuPont’s organic bottom anti-reflectant coatings (BARCs) are cross-linkable polymers that are spin cast on wafers and serve the purpose of controlling the back-reflection of light from the wafer surface into the resist material above it. DuPont’s AR™ Fast Etch Organic BARCs are based on polymers that contain a chromophore to reduce substrate reflectivity and include oxygen-rich monomers that etch quickly during the pattern transfer step. The fast etch properties of these products and the easy removal without significant loss of the resist film thickness are key to making advanced integrated circuits.
Substantially faster etch rates than the organic photoresist
AR™ Fast Etch Organic BARCs etch 30% faster than photoresists, compared to conventional BARCs that have the same etch rate as photoresists.
Significantly faster etch rates than vacuum deposited inorganic films
DuPont’s fast etch technology minimizes resist consumption, reduces line edge roughness variations and reduces critical dimension (CD) changes after pattern transfer.
Easily removed without significant loss of the resist film thickness
AR™ Fast Etch Organic BARCs etch quickly during the pattern transfer step preserving (thinner) resist thickness which is necessary for better resolution.
Maintaining the pattern fidelity and preserving the resist pattern thickness of integrated circuits is essential for good electrical performance in high yield and for high volume manufacturing.
Figure 1. Dow AR™ Fast Etch Organic BARCs solve the issues of light reflection that impact negatively on photoresist resolution. Use of Fast Etch Organic BARC diminishes reflectance from the substrate.
Figure 2. The image on the left is an example of improved line width control when using Dow’s AR™ Fast Etch Organic BARCs. The image on the right shows a pinched line, a common defect when no organic BARC is use
Figure 3. This is an illustration of a typical patterning process flow. Dow’s AR™ Fast Etch Organic BARCs play a critical role in reflection control and etch pattern transfer.