Solid State Phenomena Vols. 103-104

Abstract: This study deals with drying induced water marks dependency on the last cleaning methods, substrate conditions, and drying pre-step delaying times, which are supposed to become a big issue with down scaling of device geometry. The data show that water marks induced by drying failure increase with increasing contact angle on the various surfaces. They are mainly composed of either silicon oxide only or silicon oxide with organic compounds. The former is removed by a dilute HF and/or hot SC-1 treatment and the latter is removed by organic removal cleaning followed by dilute HF etching.

Abstract: Recently, the reduction of pattern collapse in 193nm resists with the help of a surfactinated rinse has been widely reported in the literature [1-6]. This additional step was introduced between the DI rinse that follows the developer puddle, and the final dry spin step. The present work demonstrates that the latitude of 100nm, 90nm and 75nm dense line processes can be significantly extended with an appropriate surfactant rinse through pattern collapse reduction. Simultaneously, a considerable reduction of organic defectivity is reported on blanket resist wafers.

Abstract: In this paper, a single wafer linear IPA vapour based vertical drying technique is presented. Using salt residue tests the performance of this technique is evaluated and compared to spin drying. The equivalent film thickness of evaporating liquid is below 0.05µm for blanket wafers, which is two orders of magnitude less than with spin drying. It is also shown that the presence of surface topography (200nm high TEOS features on Si covered with a chemical oxide) does not significantly influence the drying performance. A study of the process window shows that for the setup evaluated in this work best performance is achieved when the IPA/N2 flow rate is above 20 liters per minute and the drying speed is below 8 mm/s. With a manual prototype already very good particle performance is demonstrated.