High fidelity doping paste and methods thereof

Abstract

A high-fidelity dopant paste is disclosed. The high-fidelity dopant paste includes a solvent, a set of non-glass matrix particles dispersed into the solvent, and a dopant.

1 . A method of doping a semiconductor substrate, comprising:
 depositing on a surface of a semiconductor substrate a dopant paste comprising a solvent, a set of non-glass matrix particles dispersed into the solvent, and a dopant, wherein the set of non-glass matrix particles is a set of ceramic particles selected from the group consisting of Al 2 O 3 , MgO, CeO 2 , TiO 2 , ZnO, ZrO 2 , ZrO 2-3 , and Y 2 O 3 , wherein the dopant is selected from the group consisting of phosphorous dopant, arsenic dopant, antimony dopant, boron dopant and gallium dopant; and   heating the dopant paste on the surface of the semiconductor substrate to diffuse the dopant into the semiconductor substrate.   
     
     
         2 . A method of  claim 1 , wherein the dopant paste further comprises a binder. 
     
     
         3 . A method of  claim 1 , wherein the dopant constitutes 10-19 wt % of the paste. 
     
     
         4 . A method of  claim 1 , wherein the heating temperature is about 800° C. to 1050° C. 
     
     
         5 . A method of  claim 1 , wherein the solvent is an organic solvent with boiling point greater than about 200° C. 
     
     
         6 . A method of  claim 1 , wherein the solvent is selected from the group consisting of a solvent with a linear or cyclic structure, a solvent with saturated or unsaturated hydrocarbon parts, a hydrocarbon-based solvent, an alcohol, a thiol, an ether, an ester, an aldehyde, a ketone, and combinations thereof. 
     
     
         7 . A method of  claim 5 , wherein the binder is a polymer soluble in the organic solvent. 
     
     
         8 . A method of  claim 5 , wherein the binder is one of a polyacrylate, a polyacetal, a polyvinyl, a cellulose, and copolymers thereof. 
     
     
         9 . A method of  claim 1 , wherein the dopant is an n-type dopant precursor or a p-type dopant precursor. 
     
     
         10 . A method of  claim 9 , wherein the n-type dopant precursor is one of an n-type liquid, an n-type solid, and an n-type polymer. 
     
     
         11 . A method of  claim 10 , where in n-type liquid is one of H 3 PO 4  and organophosphate. 
     
     
         12 . A method of  claim 10 , wherein n-type solid is one of P 2 O 5 , Na 3 PO 4 , AlPO 4 , AlP, and Na 3 P. 
     
     
         13 . A method of  claim 10 , wherein n-type polymer is one of a polyphosphonate and a polyphosphazene. 
     
     
         14 . A method of  claim 9 , wherein the p-type dopant precursor is one of a p-type liquid, a p-type solid, a p-type binary compound, and a p-type polymer. 
     
     
         15 . A method of  claim 14 , wherein the p-type liquid is B(OR) 3 . 
     
     
         16 . A method of  claim 14 , wherein the p-type solid is one of B(OH) 3 , NaBO 2 , Na 2 B 4 O 7 , and B 2 O 3 . 
     
     
         17 . A method of  claim 14 , wherein the p-type binary compound is one of boronitride, boron carbide, boron silicide and elementary boron. 
     
     
         18 . A method of  claim 14 , wherein the p-type polymer is one of a polyborazole, and a organoboron-silicon. 
     
     
         19 . A method of  claim 1 , wherein the average diameter of the set of the non-glass matrix particles is less than 25 microns. 
     
     
         20 . A method of  claim 1 , wherein the set of non-glass matrix particles is a set of ceramic particles selected from the group consisting of TiO 2  and ZrO 2 . 
     
     
         21 . A method of  claim 1 , wherein the semiconductor substrate is a silicon substrate of a solar cell. 
     
     
         22 . A method of  claim 1 , wherein the paste is deposited in such a way that upon said heating a doped pattern is formed on the substrate. 
     
     
         23 . A method of  claim 22 , wherein said doped pattern is a solar cell doped pattern.