California Code, Probate Code - PROB § 9800

(a) Subject to subdivision (c), after authorization by order of court obtained under this chapter upon a showing that it would be to the advantage of the estate, the personal representative may borrow money on a note, either unsecured or to be secured by a security interest or other lien on the personal property of the estate, or any part thereof, or to be secured by a mortgage or deed of trust on the real property of the estate, or any part thereof, and may give a security interest or other lien on the personal property of the estate, or any part thereof, or a mortgage or deed of trust on the real property of the estate, or any part thereof, in order to do any one or more of the following:

(b) The personal representative shall apply the money to the purpose specified in the order.

(c) Where the surviving spouse has elected to have his or her share of the community real property administered in the decedent's estate, the personal representative is authorized to borrow money to be secured by a mortgage or deed of trust on the community real property of the estate, or any part thereof, only with the written consent of the surviving spouse.