To date various types of spin qubits have been developed with quantum dots including spin-1/2,singlet-triplet and exchange-only qubits.We have used a micro-magnet technique to make two spin-1/2 qubits and an entangling gate with a double quantum dot.The necessary step for further scaling up the qubit system is to increase the number of quantum dots having a suitable charge state for qubit system and improve the qubit gate fidelity as well.We have optimized the micro-magnet technique to speed up the X and Z-rotation with a high spin-flip fidelity.In addition we have fabricated three to five tunnel coupled quantum dots in series for making multiple spin qubits.