1. A cleaning method for a semiconductor substrate, the method comprising the steps of:
forming a metal layer including palladium on a semiconductor substrate; and
removing the metal layer using a removing solution containing a cerium (IV) nitrate salt,
wherein said palladium is contained in a treating solution used as a metal cap before plating.
2. The cleaning method for the semiconductor substrate as claimed in claim 1, further comprising the step of:
washing the semiconductor substrate using a cleaning solution containing hydrofluoric acid after removing the metal layer.
3. The cleaning method for the semiconductor substrate as claimed in claim 2,
wherein the content of the hydrofluoric acid contained in the cleaning solution is 0.5 to 5 weight %.
4. The cleaning method for the semiconductor substrate as claimed in claim 1,
wherein the cerium (IV) nitrate salt consists of a cerium (IV) nitrate ammonium.
5. The cleaning method for the semiconductor substrate as claimed in claim 4,
wherein the cerium (IV) nitrate ammonium is contained in the removing solution at the content of 5 to 30 weight %.
6. The cleaning method for the semiconductor substrate as claimed in claim 1,
wherein the removing solution containing the cerium (IV) nitrate salt further contains at least one acid selected from the group consisting of nitric acid, acetic acid, iodic acid and chloric acid.
7. The cleaning method for the semiconductor substrate as claimed in claim 6
wherein the total content of the acid contained in the removing solution is 1 to 30 weight %.
8. The cleaning method for the semiconductor substrate as claimed in claim 1,
wherein the removing solution containing the cerium (IV) nitrate salt further contains nitric acid.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of routing Call Detail Records (CDRs) for a subscriber to a billing center associated with the subscriber, wherein the subscriber is associated with a home network and is operating in a foreign network, and the billing center is associated with the subscriber in the subscriber’s home network, the method comprising the steps of:
receiving in a serving Mobile Switching Center (S-MSC) in the foreign network, a registration message from a mobile terminal associated with the subscriber;
sending a location updating message from the S-MSC to the subscriber’s Home Location Register (HLR) in the home network of the subscriber;
receiving in the S-MSC, a Mobile Application Part (MAP) data message from the HLR with subscriber profile information for the subscriber, said subscriber profile information including an Internet Protocol (IP) address of the billing center associated with the subscriber in the subscribers home network, wherein the billing center IP address is included in one of the MAP messages InsertSubscriberData, DeleteSubscriberData, and SendroutingInforesult;
storing the subscriber profile information in a Visitor Location Register (VLR) in the foreign network;
receiving thereafter, a call origination message from the mobile terminal;
in response to the call origination message, retrieving from the VLR, the IP address of the billing center associated with the subscriber;
establishing a connection between the mobile terminal and a called subscriber;
generating CDRs at regular intervals while the connection is established, said generating step including placing into a header of each CDR, the IP address of the billing center associated with the subscriber; and
immediately sending, through the S-MSC, each CDR via an IP network to the billing center associated with the subscriber.
2. The method according to claim 1, wherein said home and foreign networks are GSM networks.
3. The method according to claim 1, wherein said home and foreign networks are GPRS networks or UMTS networks.
4. The method according to claim 1, further comprising utilizing the CDRs by the billing center to perform near real time billing for the subscriber operating in the foreign network.
5. The method according to claim 1, further comprising utilizing the CDRs to control service availability to the subscriber.
6. The method according to claim 1, further comprising utilizing the CDRs by the billing center to perform fraud control for the subscriber operating in the foreign network.