Methods for fabricating devices containing red line emitting phosphors
Methods for fabricating coated semiconductor elements are presented. The methods include the steps of combining a phosphor of formula I and a polymer binder to form a composite material, providing a semiconductor wafer including In i Ga j Al k N, wherein 0≤i; 0≤j; 0≤k, and a sum of i, j and k is equal to 1, coating the composite material on a surface of the semiconductor wafer to form a coated semiconductor wafer, and dicing the coated semiconductor wafer using a cutting fluid apparatus to form one or more coated semiconductor elements. A cutting fluid of the cutting fluid apparatus includes a C 1 -C 20 alcohol, a C 1 -C 20 ketone, a C 1 -C 20 acetate compound, acetic acid, oleic acid, carboxylic acid, a source of A, silicic acid, or a combination thereof.
1. A method, comprising:
combining a phosphor of formula I and a polymer binder to form a composite material, wherein the phosphor of formula I is represented as:
A x [(M,Mn)F y ] (I)
providing a semiconductor wafer comprising In i Ga j Al k N, wherein 0≤i; 0≤j; 0≤k, and wherein a sum of I, j and k is equal to 1;
coating the composite material on a surface of the semiconductor wafer to form a coated semiconductor wafer; and
dicing the coated semiconductor wafer using a cutting fluid apparatus to form one or more coated semiconductor elements, wherein a cutting fluid of the cutting fluid apparatus comprises a C 1 -C 20 alcohol, a C 1 -C 20 ketone, a source of A, silicic acid, or a combination thereof,
wherein A independently at each occurance is Li, Na, K, Rb, Cs, or a combination thereof, M is Si, Ge, Sn, Ti, Zr, Al, Ga, In, Sc, Hf, Y, La, Nb, Ta, Bi, Gd, or a combination thereof, x is an absolute value of a charge of an [(M, Mn)F y ] ion; and y is 5, 6, or 7.
2. The method according to claim 1 , wherein the cutting fluid comprises ethanol, acetone, isopropyl alcohol, tertiary butyl alcohol, or a combination thereof.
3. The method according to claim 1 , wherein the source of A comprises KF, KCl, KBr, CaF 2 , a compound of formula II, or a combination thereof,
A x [MF y ] II.
4. The method according to claim 1 , wherein the step of combining the phosphor of formula I and the polymer binder comprises mixing the phosphor of formula I and the polymer binder homogeneously with a stirring rate less than 500 rpm.
5. The method according to claim 4 , wherein the stirring rate is less than 300 rpm.
6. The method according to claim 1 , wherein the polymer binder is substantially free of water, substantially free of a base, or substantially free of water and the base.
7. The method according to claim 1 , wherein the polymer binder comprises a silicone or a silicone derivative, an epoxy or a low temperature glass.
8. The method according to claim 1 , further comprising heat-treating the coated semicondutor wafer prior to dicing the coated semiconductor wafer, wherein the step of heat-treating is carried out at a temperature less than 200 degrees Celsius.
9. The method according to claim 8 , wherein the temperature is less than 150 degrees Celsius.
10. The method according to claim 1 , further comprising coupling electrical leads to the one or more coated semicondutor elements to form one or more LED chips.
11. The method according to claim 1 , wherein A is K and M is Si.
12. A method, comprising:
combining K 2 [SiF 6 ]:Mn 4+ and a polymer binder to form a composite material;
providing a semiconductor wafer comprising In i Ga j Al k N, wherein 0≤i; 0≤j; 0≤k, and wherein a sum of I, j and k is equal to 1;
coating the composite material on a surface of the semiconductor wafer to form a coated semicondutor wafer;
dicing the coated semiconductor wafer using a cutting fluid apparatus to form one or more coated semiconductor elements, wherein a cutting fluid of the cutting fluid apparatus comprises K 2 [SiF 6 ]; and
coupling electrical leads to the one or more coated semiconductor elements to form one or more LED chips.