content_image/933027.jpg content_image/933028.jpg content_image/933030.jpg content_image/933031.jpg content_image/933032.jpg content_image/933033.jpg
[0158] Dissolution Inhibitor 

[0159] Various dissolution inhibitors can be utilized in this invention. Ideally, dissolution inhibitors (Dis) for the far and extreme UV resists (e.g., 193 nm resists) are designed/ chosen to satisfy multiple materials needs including disso› lution inhibition, plasma etch resistance, and adhesion behavior of resist compositions comprising a given DI additive. Some dissolution inhibiting compounds also serve as plasticizers in resist compositions. 

[0160] A variety of bile-salt esters (i.e., cholate esters) are particularly useful as Dis in the compositions of this inven› tion. Bile-salt esters are known to be effective dissolution inhibitors for deep UV resists, beginning with work by Reichmanis et al. in 1983. (E. Reichmanis et al., "The Effect of Substituents on the Photosensitivity of 2-Nitrobenzyl Ester Deep UV Resists", J. Electrochem. Soc. 1983, 130, 1433-1437.) Bile-salt esters are particularly attractive choices as Dis for several reasons, including their availabil› ity from natural sources, their possessing a high alicyclic carbon content, and particularly for their being transparent in the Deep and vacuum UV region of the electromagnetic spectrum (e.g., typically they are highly transparent at 193 nm). Furthermore, the bile-salt esters are also attractive DI choices since they may be designed to have widely ranging hydrophobic to hydrophilic compatibilities depending upon hydroxyl substitution and functionalization. 

[0161] Representative bile-acids and bile-acid derivatives that are suitable as additives and/or dissolution inhibitors for this invention include, but are not limited to, those illustrated below, which are as follows: cholic acid (IV), deoxycholic acid (V), lithocholic acid (VI), t-butyl deoxycholate (VII), t-butyl lithocholate (VIII), and t-butyl-3-a-acetyl lithocho› late (IX). Bile-acid esters, including compounds VII-IX, are preferred dissolution inhibitors in this invention. 

<img src='content_image/933027.jpg'>

<img src='content_image/933028.jpg'>

<img src='content_image/933030.jpg'>

<img src='content_image/933031.jpg'>

<img src='content_image/933032.jpg'>

<img src='content_image/933033.jpg'>

IV 

V 

[0162] The amount of dissolution inhibitor can vary depending upon the choice of polymer. When the polymer lacks sufficient protected acid group for suitable image forming a dissolution inhibitor can be used to enhance the image forming properties of the photoresist composition. 

[0163] Other Components 

[0164] The compositions of this invention can contain optional additional components. Examples of additional components which can be added include, but are not limited 

-continued 

VI 

VII 

VIII 

IX 

