Chemical bath deposition method for fabrication of semiconductor films

A chemical bath deposition (CBD) method for forming thin films on plane substrate surfaces, comprising:

• processing vertically travelling plane substrates with their surfaces to be deposited wetted by a number of spray nozzles but the backsides remaining dry with air knives during the whole process, and with their surfaces to be deposited firstly washed with clean deionized water, then sprayed by a freshly mixed reaction solution, followed by a number of spray steps with a series of gradually aged reaction solutions, and finally washed, rinsed and dried;
• maintaining the workpiece and the solutions at a constant enhanced reaction temperature by preheating all of the reactant solutions, deionized water and the air before they enter a well isolated reactor, and heating the gradually aged solution underneath the solution groove;
• mixing the CBD solution in seconds from two or more preheated reactant solutions plus preheated deionized water inside a rounded or pear shaped device with a small outlet;
• spraying the clean deionized water, freshly mixed and gradually aged reaction solutions with a series of combinations composed of solution pipes, spray nozzles, and pumps or compressed air nozzles;
• spraying the freshly mixed reaction solution continuously onto the surfaces of a series of vertically travelling plane substrates, collecting the sprayed and gradually aged solution and spraying it back onto the travelling substrate surfaces continuously until the predicted film thickness is obtained;
• washing the residue solution away from the deposited surface using minimum rinsed water to reduce volumes of the waste to be treated and the deionized rinsing water.