Fsi Corporation

Don C Burkman

David D Schumacher

Charlie A Peterson

Jitesh R Mehta

Cooky Mezaki

A process for drying semiconductor wafers or similar substrates maintains the substrates in a static position to avoid the generation of undesired particulate. The substrates are maintained within the apparatus at an angle of approximately 30.degree. from the vertical to facilitate complete drainage of the processing fluid. According to this invention, the substrates are positioned in the chamber of the apparatus at the appropriate angle, the chamber is closed in a fluid tight seal and filled with the processing fluid, until the fluid overflows through a vacuum valve. While maintaining the chamber completely filled, vacuum aspiration is continued to degas the chamber. While continuing vacuum aspiration of the chamber, a vacuum assisted drain valve is opened, and clean dry inert gas is introduced above the draining fluid. The draining step assures that any droplets remain with the draining fluid so that the substrates emerge dry as the fluid drains away. The inert gas flow is discontinued and vacuum aspiration is maintained briefly after the chamber has drained. The vacuum aspiration is discontinued and the chamber is repressurized to essentially ambient pressure prior to opening the chamber to remove the dry substrates.

Apparatus and process for static drying of substrates

In a chemical processing system for processing substrates or wafers in the production of electronic devices or integrated circuit chips, a rinsing step of simultaneously thoroughly rinsing the substrate in the processing chamber while the chemical supply lines and chemical spray posts are also being thoroughly rinsed with rinse water directed down a drain and without spraying into the processing chamber by controlling the pressure or rate of flow of rinsing water through the liquid chemical supply lines and chemical spray post passages and orifices so that most of the rinsing water will flow through an open drain valve and down the drain and only a trickle of water is permitted to flow outwardly through the spray orifices of the chemical spray post so that none of the rinsing water with dilute traces of chemical is sprayed onto the substrates in the processing chamber. A separate and dedicated rinsing water spray post or head is provided for directing rinsing water atomized by inert gas such as nitrogen to instantaneously commence rinsing of the wafers in the processing chamber. The liquid chemical spray posts are provided with pipe connections to the chemical supply passages within the spray post to accommodate rinsing water flow through the passage and out through the drain ducts and through an openable drain valve to a drain so that rinsing water may freely flow through the chemical supply lines and chemical supply passages in the chemical spray heads simultaneously with the application of rinsing water from the dedicated rinsing water spray post on the chamber wall.

Rinsing in acid processing of substrates

In a chemical processing system for processing substrates or wafers in the production of electronic devices or integrated circuit chips, a rinsing step of simultaneously thoroughly rinsing the substrate in the processing chamber while the chemical supply lines and chemical spray posts are also being thoroughly rinsed with rinse water directed down a drain and without spraying into the processing chamber by controlling the pressure or rate of flow of rinsing water through the liquid chemical supply lines and chemical spray post passages and orifices so that most of the rinsing water will flow through an open drain valve and down the drain and only a trickle of water is permitted to flow outwardly through the spray orifices of the chemical spray post so that none of the rinsing water with dilute traces of chemical is sprayed onto the substrates in the processing chamber. A separate and dedicated rinsing water spray post or head is provided for directing rinsing water atomized by inert gas such as nitrogen to instantaneously commence rinsing of the wafers in the processing chamber. The liquid chemical spray posts are provided with pipe connections to the chemical supply passages within the spray post to accommodate rinsing water flow through the passages and out through the drain ducts and through an openable drain valve to a drain so that rinsing water may freely flow through the chemical supply lines and chemical supply passages in the chemical spray heads simultaneously with the application of rinsing water from the dedicated rinsing water spray post on the chamber wall.

In acid processing of substrates, such as silicon wafers in the manufacture of electronic devices, such as integrated circuit chips, the method of mixing separate chemicals together in the processing chambers and as the separate chemicals are sprayed in atomized and directional spray patterns toward and across the surfaces of the substrates, the directional spray patterns emanating from different sources and having oblique directions with respect to each other to traverse each other at the surfaces of the substrates for thorough mixing and immediate application to the wafer faces to accomplish the processing. A vented housing defines the processing chamber with spray posts spaced from each other around the periphery of the housing and mounted on the sidewall and directing atomized liquid chemical sprays toward the center at which the substrates are mounted as to cause the spray patterns to traverse each other as they sweep across the wafers.

Growing community of inventors

Excelsior, MN, United States of America

Don C Burkman