Method for manufacturing semiconductor device
View Patent ↗A method for manufacturing a semiconductor device reduces or prevents copper contamination. The method includes forming a gate electrode on a substrate; forming a first oxide layer on a front surface of the substrate including the gate electrode; depositing a nitride layer (simultaneously) on the first oxide layer and a rear surface of the substrate; depositing a second oxide layer on the nitride layer; removing the second oxide layer from the rear surface of the substrate; and forming spacers at sides of the gate electrode by etching the second oxide layer, the nitride layer, and the first oxide layer.
1. A method for manufacturing a semiconductor device, comprising:
forming a gate electrode on a substrate;
forming a first oxide layer on an entire front surface of the substrate including the gate electrode;
depositing a front surface nitride layer on the first oxide layer and a rear surface nitride layer on the rear surface of the substrate;
depositing a second oxide layer on at least the front surface nitride layer;
removing any oxide from the rear surface of the substrate by etching with a fluorinated ethylene-propylene (FEP) solution; and
forming spacers at sides of the gate electrode by etching the second oxide layer, the nitride layer, and the first oxide layer.
2. The method of claim 1 , wherein forming the first oxide layer comprises depositing a layer of oxide on front and rear surfaces of the substrate and removing the layer of oxide from the rear surface of the substrate.
3. The method of claim 1 , wherein the oxide layer on the rear surface of the substrate is formed when depositing the second oxide layer.
4. The method of claim 1 , wherein the first and second oxide layers comprise a tetraethylorthosilicate-based oxide.
5. The method of claim 1 , wherein the nitride layer comprises silicon nitride.
6. The method of claim 1 , wherein forming the nitride layer comprises low-pressure chemical vapor deposition.
7. The method of claim 6 , wherein the low-pressure chemical vapor deposition is performed at a temperature of less than 550° C.
8. The method of claim 1 , wherein the FEP solution further comprises a mixture of HF, HNO 3 , and H 2 O.
9. The method of claim 1 , wherein the FEP solution further comprises a concentrated HF:concentrated HNO 3 :H 2 O mixture having a ratio of about 1:6:3, by weight or volume.
10. The method of claim 8 , comprising etching the substrate for about six seconds.
11. The method of claim 1 , further comprising:
implanting impurity ions to the substrate at sides of the gate electrode, after forming the gate electrode.
12. The method of claim 1 , wherein the front surface nitride layer and the rear surface nitride layer are deposited simultaneously.
13. The method of claim 1 , wherein forming spacers comprises anisotropically etching the second oxide layer, the nitride layer, and the first oxide layer.